Method and apparatus for concept-based ranking of natural language discourse

ABSTRACT

Concept-based ranking is applied to the results of a search process. Concept-based ranking relies on the input query, that produced the search results, having pinnacle concept properties specified for some of its keyword-based search terms. For each record “r” of a search result, it can be assigned a concept-based ranking score as follows. For each query term “QT,” of the input query, the following can be performed. The set of occurrences of “QT,” in the record, can be determined. Based upon the pinnacle concept of “QT,” and certain characteristics of the set of occurrences, a value can be assigned to “QT.” Characteristics, of the set of occurrences, can include the type of pinnacle concept asserted by at least one sub-unit of the record in which there is an occurrence. Once each “QT” has been assigned a value, such values can be combined to produce a score for ranking the record.

As provided for under 35 U.S.C. §120, this is a continuation that claimsbenefit of the filing date of the following U.S. patent application,herein incorporated by reference in its entirety:

“Method and Apparatus For Concept-Based Classification of NaturalLanguage Discourse,” filed 2006 May 29 (y/m/d), having inventors JohnAndrew Rehling and Michael Jacob Osofsky, and application Ser. No.11/420,782 now U.S. Pat. No. 8,055,608;

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to the following three U.S. patentapplications, all of which are herein incorporated by reference in theirentirety:

“Method and Apparatus For Concept-Based Classification of NaturalLanguage Discourse,” filed 2006 May 29 (y/m/d), having inventors JohnAndrew Rehling and Michael Jacob Osofsky, and application Ser. No.11/420,782;

“Method and Apparatus For Concept-Based Searching of Natural LanguageDiscourse,” filed 2006 May 29 (y/m/d), having inventors John AndrewRehling and Michael Jacob Osofsky, and application Ser. No. 11/420,785;

“Method and Apparatus For Concept-Based Ranking of Natural LanguageDiscourse,” filed 2006 May 29 (y/m/d), having inventors John AndrewRehling and Michael Jacob Osofsky, and application Ser. No. 11/420,788;

FIELD OF THE INVENTION

The present invention relates generally to the search ofcomputer-accessible content, and more particularly to enhancing theeffectiveness of searching computer-accessible content containingnatural language discourse.

BACKGROUND OF THE INVENTION

A common activity, given the increasing availability ofcomputer-accessible content, is to generate indexed databases of suchcontent and to provide keyword-based search facilities for accessing theinformation.

For example, a large percentage of the pages, on the World-Wide Web,have been made keyword searchable by search engines. An example searchengine is GOOGLE, of Mountain View, Calif., U.S.A.

Keyword search is most effective when records, that are likely to be ofinterest to the user, can be located with terms that are highly specificto the topic of interest. In many instances, however, highly specifickeyword terms can only partly describe the topic of interest. Theproblems resulting from this inability of keywords, to more fullydescribe certain search topics, can be twofold. First, a set of recordscan be returned that is too large for the user to review in a reasonableamount of time. Second, the set of records returned can include manyrecords that are off-topic.

GOOGLE attempts to address the limitations of keywords by ranking therecords (more specifically, the web pages) returned according to a“popularity” metric. According to GOOGLE, the popularity of a web pageis proportional to the number of other web pages that point to it.

However, for many types of search topics, popularity is not anacceptable proxy for the portion of the topic that could not beadequately expressed with keywords.

An example search topic, where popularity is not an acceptable proxy, isthe search for new uses of an existing technology “ET1.” To address thissearch topic, one would like to search the entire Internet for those webpages where problems (or market needs), that technology “ET1” can beeffective at addressing, are discussed. The authors of such pages arelikely to be interested in using technology “ET1.” Unfortunately, it isdifficult to express, with keywords, the requirement that a web pageexpress or utilize the concept of “problem” or “market need.”

Another example search topic, where popularity is not an acceptableproxy, is the search for an existing technology that can address aproblem “P1.” To address this search topic, one would like to search theentire Internet for those web pages where claims of success, ataddressing “P1,” are discussed. The authors of such pages are likely tobe knowledgeable about an existing technology that can address “P1.”Unfortunately, it is difficult to express, with keywords, therequirement that a web page express or utilize the concept of “claim ofsuccess.”

It would therefore be desirable to be able to retrieve records not onlyon the basis of keywords, but also on the basis of whether a recordaddresses a concept.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, that are incorporated in and constitute apart of this specification, illustrate several embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention:

FIGS. 1A-1B depict the processes of, respectively, the indexing andsearch phases;

FIG. 1C depicts concept-based search used in conjunction withkeyword-based search;

FIG. 2A depicts a process for performing classification of a unit ofnatural language discourse;

FIG. 2B depicts the general structure of the process presented insection 2.2 (“Pseudocode and Example”);

FIG. 3 depicts an example computer system design in which the techniquesdescribed herein can be applied;

FIG. 4 depicts pseudocode for indexing;

FIGS. 5A-5B depict, respectively, pseudocode for query accepting andkeyword-based searching;

FIGS. 5C-5D depict an example procedure for implementing concept-basedranking;

FIGS. 6A-6G depict an example pseudocoded procedure(“sentence_classify”) for performing classification of a sentence;

FIGS. 7A-7B depict an example operation of query_score in thepseudocode;

FIG. 8A depicts an example query where the searcher has an existingtechnology, for making batteries last longer, and would like to findpotential licensees;

FIG. 8B depicts a page that is the same as the page of FIG. 8A, exceptthat a concept property has been added to each query term;

FIG. 8C depicts a web-based interface through which a user can selectthe CBDBs to be keyword searched;

FIG. 8D depicts a screen at which a user can specify a keyword search;

FIGS. 8E-8F depict example results of initiating a search;

FIG. 9A depicts an example concept feature database;

FIG. 9B depicts an example structure of a semantic unit;

FIG. 9C depicts a table of example syntactic relationship labels;

FIG. 9D depicts a table of example pinnacle concepts;

FIG. 9E depicts an example map from Quantifier type to base value;

FIG. 10A depicts an example input sentence 1000 for illustrating theoperation of sentence_classify;

FIG. 10B depicts a table of lexical units and part-of-speechdesignations for the example input sentence 1000;

FIG. 10C depicts an example parse structure for example input sentence1000;

FIG. 10D depicts the example parse structure of FIG. 100 seeded withQuantifier and non-Quantifier values;

FIG. 10E depict the example parse structure of FIG. 10D after Quantifierpropagation;

FIG. 10F depicts the example parse structure of FIG. 10E afterapplication of the power law to the non-negation Quantifiers;

FIG. 10G depicts the example parse structure of FIG. 10F afterapplication of thresholding to negation Quantifiers;

FIG. 10H depicts the example parse structure of FIG. 10G afterapplication of the power law to the negation Quantifiers;

FIG. 10I depicts, for the example, the assignment of a unique ID to eachQuantifier concept-value pair;

FIG. 10J depicts, for the example, back propagation of each Quantifierconcept-value pair;

FIG. 10K depicts, for the example, scaling of the non-Quantifiers withthe Quantifiers;

FIG. 10L depicts, for the example, the results of propagatingnon-Quantifier concept-value pairs and keeping, at each node for eachconcept, the concept-value pair of maximum value;

FIG. 11 depicts an example snippet to illustrate concept-based ranking;and

FIGS. 12A-12E depicts five similar sentences, labeled 1200-1204, thatare intended to be illustrative of how occurrences of the negationQuantifier “Negation,” in a sentence, can interact at governing nodes.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Reference will now be made in detail to various embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

Please refer to the Glossary of Selected Terms, included at the end ofthe Detailed Description, for the definition of selected terms usedbelow.

Table of Contents to Detailed Description 1. Concept-Based Search  1.1.Plains and Pinnacle Concepts  1.2. Combining Concept-Based andKeyword-Based Search   1.2.1. Overview   1.2.2. Two-Phase Approach  1.3.Example Search Problems   1.3.1. New Uses For An Existing Technology  1.3.2. Finding A Technology To Address A Problem  1.4. Example Search2. Concept-Based Classification  2.1. Overview   2.1.1. “reference” or“assertion” by a UNLD   2.1.2. Correlative Concepts   2.1.3. ReferenceLevel Values   2.1.4. Quantifiers and Non-Quantifiers   2.1.5.Linguistic Features   2.1.6. Complete Concept Feature Sets   2.1.7.Sub-Unit Application of Quantifiers  2.2. Pseudocode and Example  2.2.1. Parse   2.2.2. Populate Parse Structure   2.2.3. QuantifierPropagation   2.2.4. Determine Quantifier Values    2.2.4.1.Non-Negation Quantifiers     2.2.4.1.1. Sum Values On Per-Concept Basis    2.2.4.1.2. Apply PLQ    2.2.4.2. Negation Quantifiers     2.2.4.2.1.Thresholding     2.2.4.2.2. Sum Values On Per-Concept Basis    2.2.4.2.3. Apply PLQ   2.2.5. Quantifier Back Propagation   2.2.6.Scale Non-Quantifier Values With Quantifier Values   2.2.7. PropagateNon-Quantifiers   2.2.8. Select Maximum Non-Quantifiers   2.2.9. Summary3. Concept-Based and Keyword-Based Search, Pseudocode  3.1. Indexing 3.2. Query Accepting   3.2.1. Query Form   3.2.2. Page Usage Techniques  3.2.3. Example Query  3.3. Keyword-based Searching 4. Concept-BasedRanking  4.1. Overview  4.2. Scoring a Snippet Relative to a Query 5.Further Details  5.1. Pinnacle Concepts   5.1.1. Other Pinnacle Concepts  5.1.2. Multiple Pinnacle Concept Concept-Based Search   5.1.3.Deriving a Concept-Feature Database  5.2. Snippet Formation  5.3.Production Environment  5.4. Example Negation Propagation 6. Glossary ofSelected Terms

1. CONCEPT-BASED SEARCH

1.1. Plains and Pinnacle Concepts

As addressed herein, the general problem of searchingcomputer-accessible content (see Glossary for definition ofcomputer-accessible content) can be described as the utilization of anautomated process to determine occurrences of where a sought-for concept(or search topic) is referred to in natural language discourse. Naturallanguage discourse “refers” to (or references) a concept “C” when ituses linguistic expressions in such a way that “C” is regarded asexpressed, used or invoked by an ordinary reader of the human language“L” in which the discourse is written.

Herein, two broad categories of search topic are defined: “plainsconcepts” and “pinnacle concepts.”

Plains concepts are relatively easy to search for because references tothem can be detected by the occurrence of certain keywords (see Glossaryfor definition of keyword-based search). A plains concept can becharacterized as follows. It is a concept that, in general, isinfrequently used or expressed in natural language discourse. The set oflexical units, that refer to the plains concept, to some degree, is verysmall. A plains concept tends to be low-level (or “concrete”) andtightly linked to particular types of objects. Most of the lexicalunits, in any given human language, are used to indicate a plainsconcept. An example plains concept is the concept of an “apple.” Thereare very few lexical units of English, other than the lexical unit“apple” itself, that refer to the concept of “appleness.” As aconvention herein, to indicate that a lexical unit is being used as asymbol for a concept, as opposed to using that lexical unit as a lexicalunit, the lexical unit will be capitalized and enclosed in doublequotes. For example, “Apple,” as used herein, is a symbol for theconcept of an “apple.”

References to pinnacle concepts are not amenable to detection by the useof keywords. A pinnacle concept can be characterized as follows. It is aconcept that, in general, is frequently used or expressed in naturallanguage discourse. The set of lexical units, that refer to the pinnacleconcept, to some degree, is very large. A pinnacle concept tends to behigh-level (or “abstract”) and lightly linked to particular types ofobjects. An example pinnacle concept is the concept of “goodness”(referred to herein as “Good”). There are many lexical units of English,other than just the lexical unit “good,” that refer to, at least to somedegree, the concept “Good.”

Pinnacle concepts are not amenable to keyword search for at least thefollowing reasons. First, the fact that a pinnacle concept is indicatedby a very large set of lexical units means that a very large set ofkeywords would need to be used. Second, even if one were to search forthe very large set of keywords required, the “strength” or probabilitywith which different lexical units indicate a pinnacle concept candiffer widely. Further, the initial “strength” or probability with whicha pinnacle concept “C” is indicated, can vary greatly (in either thepositive or negative direction) depending upon the presence of otherpinnacle concepts that are within sufficient proximity to “C” (whereproximity to “C” is determined by the rules of the human language inwhich “C” is expressed).

The term “concept-based search,” as used herein, refers to the reliableidentification, within computer-accessible content that representsnatural language discourse, of instances in which a particular pinnacleconcept “C” is referenced.

1.2. Combining Concept-Based and Keyword-Based Search

1.2.1. Overview

Concept-based search can be accomplished, on computer-accessiblecontent, according to a particular unit of natural language discourse(or UNLD). For example, the UNLD can be the sentence. In this case, eachsentence of the computer-accessible content can be separately analyzedfor whether it references a particular pinnacle concept.

Concept-based search can be used in conjunction with keyword-basedsearch as follows. The process is explained in conjunction with FIG. 1C.

An input query is accepted from the user. Step 121. The input queryspecifies both a concept and keywords to be searched for.

The next (or first) match of the keyword search, in thecomputer-accessible content, can be found. Step 122.

If a match, of the keyword query, is found (the “yes” path of step 123),a locality to that keyword match is determined (step 124).

If a match, of the concept query, is found within the locality (the“yes” path of step 125), a record, that includes both the keyword andconcept matches, is added to the search results (step 126). If a match,of the concept query, is not found within the locality (the “no” path ofstep 125), a next keyword match can be searched for. Step 122. A nextkeyword match can also be searched for after a record (in step 126) isadded to the search results.

When a next keyword match is no longer found (the “no” path of step123), the collected records can be ranked (step 127) and displayed forthe user (step 128).

The above-described process, that performs the keyword search before theconcept search, can be desirable if the identification of a match, ofthe keyword query, is less computationally expensive than identificationof a match of the concept query. Alternatively, step 122 can obtain anext match of the sought-for concept in the computer-accessible contentand step 125 can determine whether the locality to the concept matchesthe keyword search.

Regardless of whether step 122 is searching for a keyword or conceptmatch, if it is assumed the match occurs within a UNLD “u” of thecomputer-accessible content, the locality to the match (that is thensearched in step 125) can be a certain number of UNLDs surrounding “u.”A package of text comprising “u,” and a certain number of UNLDssurrounding “u,” is referred to herein as a “snippet.” An example UNLDis a sentence.

The snippet can be chosen to be of a sufficient size such that, on astatistical basis, it provides sufficient factual context for a user tounderstand whether “u” is relevant to his or her search topic.

1.2.2. Two-Phase Approach

When using concept-based search with keyword-based search, it can beuseful, from an efficiency perspective, to divide the process into twophases. These two phases can be referred to as the “indexing phase” andthe “search phase.” The indexing phase is the temporally earlier phasein which concept-based searching is performed and a database, referredto herein as a concept-based database, is generated. In the searchphase, keyword-based searching is performed on the concept-baseddatabase created during the indexing phase.

An illustration, of the process of the indexing phase, is shown in FIG.1A. During the indexing phase the computer-accessible content issearched, according to units of natural language discourse, forreferences to a concept “C.” In FIG. 1A, the unit of natural languagediscourse can be a sentence. More specifically, in step 101 a next (orfirst) UNLD (e.g., a next sentence) of the computer-accessible contentcan be obtained. If a next UNLD is not found, the indexing phase ends(the “no” path of step 102 is followed). If a next UNLD is found, it istested (by step 103) for whether it is indicative of a sought-forconcept “C.” If a UNLD “U” references “C,” then (the “yes” path of step103 is followed) a snippet is determined around “U” (step 104) and thesnippet is added (step 105) to a concept-based database (CBDB). Additionof the snippet to the CBDB also includes indexing the snippet such thatit can be efficiently keyword searched, along with other snippets addedto the CBDB. The concept “C,” that serves as a criteria for whether asnippet is added to the CBDB, is referred to herein as the “organizingconcept” for the CBDB. Following indexing of the snippet, the indexingprocess can continue by looping back (from step 105) to the step ofobtaining a next UNLD for analysis (at step 101). If a UNLD “U” does notreference “C,” then (by the “no” path of step 103) the process can loopback to the step of obtaining a next UNLD for analysis (at step 101).

An illustration, of the process of the search phase, is shown in FIG.1B. In step 111, a keyword-based search query is accepted from the user.The user also selects the particular CBDB to be searched by thekeyword-based query. In step 112 a keyword search is performed of theselected CBDB. The results of the keyword search are ranked according toan appropriate metric. Step 113. The ranked search result is output tothe user. Step 114.

1.3. Example Search Problems

1.3.1. New Uses for an Existing Technology

An example type of a search problem, that can be usefully addressed byconcept-based search, is the search for new uses of an existingtechnology “ET1.” This search topic can also be referred to as a searchfor “market needs.”

An approach to searching for new uses of an ET1 is described in thissection using the above-described two-phase process.

For this search problem, the computer-accessible content to be searchedcan be an input database that is comprised of a large portion of thosepages posted on the Internet that are technologically oriented. Theinput database can be obtained through known techniques, such as webcrawling, where the web crawling is “seeded” to start fromtechnologically oriented web sites. An example suitable web crawlingprogram is the open-source program called “Heritrix.” Heritrix is madeavailable through VA Software of Freemont, Calif., U.S.A. The inputdatabase can also be compiled from any other suitable sources ofcomputer-accessible data. Examples of such other sources include thefollowing: CD-ROMs; record-oriented databases (relational or otherwise);and a company intranet.

A CBDB can be compiled, from the input database, according to theorganizing concept “Bad.” The concept “Bad” occurs, in a unit of naturallanguage discourse (typically, a single sentence), when that unit refersto, with regard to something, a negative, detriment or badness that isof, or related to, that something.

The CBDB formed, when the organizing concept is “Bad,” shall be referredto herein as CBDB(“Bad”). When searching for a new use for an existingtechnology, CBDB(“Bad”) can be useful since it contains statements wherea problem of some kind is being discussed. It is reasonable to assumethat a party encountering a problem is likely to wish to expendresources to address the problem.

The second step, in finding new uses for an ET1, is to keyword searchCBDB(“Bad”) to select problem discussions that are likely to be about atype of problem that ET1 can help address.

1.3.2. Finding a Technology to Address a Problem

Another example type of a search problem, where concept-based search canbe useful, is the search for a technology to address an existing problem“EP1.” This search topic can also be referred to as a search for “marketclaims” since the search is for a technology that is accompanied byclaims that would lead one to conclude that it might be capable ofaddressing “EP1.”

Searching for a technology applicable to an EP1 can be accomplishedaccording to the same two-phase process discussed above (for finding anew application of an existing technology), except that the organizingconcept for the CBDB is “Good” rather than “Bad.” The concept “Good”occurs when a unit of natural language discourse refers to, with regardto something, a positive, benefit or goodness that is of, or related to,that something.

The CBDB formed, when the organizing concept is “Good,” shall bereferred to herein as CBDB(“Good”). When searching for a technology toaddress a problem, CBDB(“Good”) can be useful since it containsstatements where a solution of some kind is being discussed. Keywordsearch can be used to filter CBDB(“Good”) for those solutions that maybe useful for addressing the particular factual problem at issue.

1.4. Example Search

While discussed further, in section 3 (“Concept-Based and Keyword-BasedSearch, Pseudocode”) and section 4 (“Concept-Based Ranking”), thissection introduces an example search that is the type of search problempresented above in section 1.3.1 (“New Uses For An ExistingTechnology”).

For this example, we assume that CBDB(“Bad”) and CBDB(“Good”) havealready been compiled. The user has an existing technology, for makingbatteries last longer, and would like to find potential licensees. Asdiscussed further in below section 5.3 (“Production Environment”), theuser can specify his or her search through a web-based interface.

FIG. 8C depicts a screen 802 which a user could view through a web-basedinterface. As can be seen, the user can select the CBDBs to be keywordsearched by putting a check mark in the appropriate boxes. For screen802 two CBDBs are available: “Market Needs” (which is another name forCBDB(“Bad”)) and “Market Claims” (which is another name forCBDB(“Good”)). In this case, the user has only checked the “MarketNeeds” CBDB. The user can then select the “next” button to move to anext screen in the search formulation process.

FIG. 8D depicts a screen 803 at which a user can specify a keywordsearch. The particular form of keyword entry provided is described belowin section 3.2.1 (“Query Form”). The unit of query specification,provided for by screen 803, is called a “page” (which is why screen 803is referenced as “PAGE 803” in FIG. 8D). While described further belowin section 3.2.2 (“Page Usage Techniques”), the general strategy is thata page “p” is written such that any snippet “s,” that satisfies “p,” islikely to be of interest to the user for his or her particular searchtopic. Further, within a satisfied page “p,” the more query terms thatare satisfied, the more likely “s” is to be of interest to the user.

FIG. 8B depicts a page 801, that is the same as page 803, except that auser has completed the page with search terms intended to locatesnippets that discuss problems with battery power. A detailed discussionof FIG. 8B is found in below section 4 (“Concept-Based Ranking”). Inexplaining page 801, section 4 first refers to section 3.2.3. (“ExampleQuery”). Section 3.2.3 explains a page 800 (of FIG. 8A) that is asimpler form of page 801. Page 800 differs from page 801 in lacking the“concept property” field.

Example results, of initiating a search based upon page 801, aredepicted in FIGS. 8E and 8F. For this search, a total of 221 snippetswere found. These snippets are ranked according to how well eachsatisfies the query of page 801. FIG. 8E depicts snippets 1 and 2, ofthe 221 snippets (which are also labeled, for purposes of clarity, assnippets 830 and 831). FIG. 8F depicts snippets 3 and 4, of the 221snippets (which are also labeled, for purposes of clarity, as snippets832 and 833). If the user decides a snippet is relevant to the searchproblem, a link to the source web page, from which the snippet wasextracted, is provided below each snippet. For each snippet displayed,the sentence of the snippet, that caused the snippet to be included inCBDB(“Bad”), is underlined. The default snippet size, for the particularCBDB(“Bad”) searched, is 5 sentences per snippet with the centralsentence being the one that caused the snippet to be included inCBDB(“Bad”). As can be seen in FIGS. 8E and 8F, snippets 830 to 832 areeach five sentences long while snippet 833 is only two sentences longbecause it is limited by “edges,” in the source text, both before andafter the underlined sentence.

An examination of snippet 830 shows that it is certainly related to thetopic of battery life, but that it is not likely to lead to a party thatwould be interested in longer lasting batteries. In fact, this snippetappears to be discussing an application where batteries that have alonger life is not desirable.

An examination of snippet 831 shows that it is not related to the topicof battery life. This snippet appears to be describing a struggle tokeep a laboratory running during a period of civil unrest in a formerSoviet satellite country.

Snippets 832 and 833, however, appear to be “on point.” Snippet 832discusses a wireless keyboard and mouse, which is certainly anapplication where longer lasting batteries are useful. Snippet 833discusses a digital camera, another application where longer lastingbatteries are useful.

2. CONCEPT-BASED CLASSIFICATION

2.1. Overview

The term “concept-based classification” (or simply “classification”), asused herein, refers to the identification of whether a pinnacle conceptis asserted by a unit of natural language discourse (UNLD) written in ahuman language “L.” An example UNLD is the sentence.

2.1.1. “Reference” or “Assertion” by a UNLD

A UNLD “refers” to a concept “C” when that UNLD uses linguisticexpressions in such a way that “C” is regarded as expressed, used orinvoked by an ordinary reader of “L.” Repeated application ofconcept-based classification is the basis for concept-based search (asdiscussed above). The unit of natural language discourse focused-onherein is the sentence.

Reference to a concept “C” can apply regardless of whether the UNLD,that refers to “C,” has been interpreted relative to the UNLD'sQuantifier concepts (see section 2.1.4 for definition of Quantifier).Thus, for example, while a UNLD may refer to a concept “C,” applicationof a Quantifier of type “negation,” in a later interpretive process ofthe UNLD, can invert the concept (i.e., not “C” is determined to be theconcept actually referred to by the UNLD). A concept “C,” that isdetermined to be referenced by a UNLD “x,” after application of itsQuantifiers, is said to be asserted by “x.”

As an example, a sentence “s” can contain the expression “not good.”While “s” can be said to refer to the concept “Good,” “s” does notassert “Good.” This is because application of the Quantifier negation(invoked by the lexical unit “not”) inverts the concept referenced tobeing “Bad.” Thus “Bad” is asserted by “s” (and “Bad” is also referencedby “5”).

2.1.2. Correlative Concepts

Two pinnacle concepts, whose identification is focused-on in thissection, are “Good” and “Bad.” The concepts “Good” and “Bad,” whenpaired, are an example of what is called, herein, “correlativeconcepts.” In general, a concept “A” and a concept “B” are definedherein to be correlative if not “A” means “B” and not “B” means “A.”“Good” and “Bad” are correlative concepts since, in general, an ordinaryreader regards something that is not “Good” as “Bad” and something thatis not “Bad” is “Good.”

The “dimensional concept,” for the correlative concepts “Good” and“Bad,” is referred to herein as “Quality.” In general, a dimensionalconcept is the broader concept that encompasses both concepts of a pairof correlative concepts.

2.1.3. Reference Level Values

During the classification process, each pinnacle concept identified canassume a “reference level” value from within a range of values.Depending on the application, the magnitude of the reference level valuecan be proportional to: the “strength” with which the pinnacle conceptis referenced, the probability that a pinnacle concept is referenced orboth the “strength” and probability of a pinnacle concept reference. Anexample reference level range is 0 to 1, with 0 meaning the reference isof no strength and/or probability and a 1 meaning the reference is ofmaximal strength and/or probability. To give an example, consider theconcept “Bad.” The word “bad” itself could be regarded as referring to“Bad” with a reference level that is, on a scale of 0 to 1, 0.75.However, the phrase “very bad” needs to be assigned a reference levelgreater than 0.75 (but still less than 1.0). This is because the word“very” can be regarded as increasing the “strength” and/or probabilitythat “Bad” is referred to by the word “bad.”

2.1.4. Quantifiers and Non-Quantifiers

FIG. 2A presents a process for performing classification of a unit ofnatural language discourse (or UNLD). As can be seen, the process beginsby identifying the pinnacle concepts referred to by the UNLD (step 201).The types of pinnacle concepts that can be referred to include both“Quantifier” and “non-Quantifier” concepts. A Quantifier concept is aconcept that can modify the reference level assigned to a non-Quantifierconcept. A subset, of the set of non-Quantifier concepts, is referred toherein as the set of “Characteristic” concepts. A Characteristic conceptis so-called because it describes a characteristic or property of anentity. For the phrase “very bad,” the word “bad” can be regarded as areference to a non-Quantifier concept (i.e., the concept “Bad”) whilethe word “very” can be regarded as a reference to a Quantifier concept.The effect of “very” is to modify (i.e., it intensifies) the referencelevel of the reference to the non-Quantifier concept “Bad.” Examples ofQuantifier and non-Quantifier concepts are shown in FIG. 9D. As can beseen, “Good” and “Bad” are examples of non-Quantifier concepts. “Good”and “Bad” are also, more specifically, examples of Characteristicconcepts. The Quantifier concept “Intensify” is the concept referencedby the word “very” in the phrase “very bad.” Determination, of referenceto pinnacle concepts by a UNLD, can be accomplished as follows.

2.1.5. Linguistic Features

For each pinnacle concept “C” (either Quantifier or non-Quantifier),whose reference is to be determined, a set can be compiled that isreferred to herein as a “concept feature set.” A concept feature set “s”is a set of linguistic features (see following paragraph for definitionof “linguistic feature”). Each member of “s” can be used in connectionwith a normal, and helpful, reference to “C” in a human language “L.”The occurrence of a member of “s,” in a unit of natural languagediscourse (UNLD), is an indication that, with some reference level “r,”the UNLD refers to “C.”

The term linguistic feature can be defined as follows: any patternwithin a human language “L,” that is amenable to algorithmic detectionand that has been determined to indicate, within the discourse withinwhich it occurs, the expression or use of at least one pinnacle concept.An example of a lower-level pattern, sought to be matched by alinguistic feature, is a single lexical unit. However, another examplepattern, that would be higher-level, can be as follows: any sequence ofthree words, limited only by each of the three words being a particularpart of speech (e.g., a determiner followed by an adjective followed bya noun).

2.1.6. Complete Concept Feature Sets

In general, it is desirable for a concept feature set to be “complete.”A test, for what constitutes a “complete” concept feature set, can bestated as follows. Let “corpus_x” represent the set of all normal andhelpful UNLDs, that have been written in a human language “L,” in whicha pinnacle concept, “x,” is referenced. Let “instances_x” representsize, in UNLDs, of “corpus_x.” Let a concept feature set for “x,” thatmay or may not be complete, be called “cfs_x.” Let “cfs_x” be applied to“corpus_x” and let “all_positives” be the set of all UNLDs, of“corpus_x,” indicated by “cfs_x” as referring to “x.” Let “correct_x”represent the size of a subset of “all_positives,” wherein a member of“all_positives” is a member of the subset if it actually refers to “x.”Let “incorrect_x” represent the size of a subset of “all_positives,”wherein a member of “all_positives” is a member of the subset if it doesnot actually refer to “x.” Concept feature set “cfs_x” is complete if:

$\begin{matrix}{\frac{correct\_ x}{incorrect\_ x} > {min\_ correct}} & (i) \\{\lbrack {1 - \frac{correct\_ x}{instances\_ x}} \rbrack < {max\_ missed}} & ({ii})\end{matrix}$

For example, if “min_correct” (or minimum correct) is set at 0.9,satisfying (i) means that, among the UNLDs indicated by “cfs_x” aspositive for “x,” better than 90 percent of them are actually positivefor “x.” If “max_missed” (or maximum missed) is set at 0.1, satisfying(ii) this means that, if cfs_x is applied to corpus_x, less than 10percent, of the actual occurrences of references to “x,” will be missed(i.e., will not be identified as references to “x”).

In general, in order to make the task of finding a complete “cfs_x” aseasy as possible, one will choose the smallest acceptable value for“min_correct,” and largest acceptable value for “max_missed,” based uponthe amount of accuracy required by the particular application. Forexample, acceptable values for “min_correct” and “max_missed” can bedetermined empirically.

Further, since “corpus_x” is too large to be handled in practice, anapproximation of corpus_x, that is a representative sampling ofcorpus_x, can be used. In this case, the values used, for instances_x,correct_x and incorrect_x, are approximations to their actual values.

2.1.7. Sub-Unit Application of Quantifiers

Once a pinnacle concept “C” has been identified as referenced, it can beuseful to identify the particular sub-units (or parts), of the UNLD,responsible for such reference. For example, identification of thesub-units can allow Quantifier concepts to more accurately modify thereference levels of non-Quantifiers. Identification of the sub-units canbe accomplished by application of the rules of the human language “L” inwhich the UNLD is expressed. This step is depicted, in FIG. 2A, by step202. The granularity of the sub-units identified can vary based upon theapplication. An example level, of sub-unit identification, is thelexical unit level.

For each sub-unit “x” of the UNLD, where a non-Quantifier and aQuantifier concept are found referenced, the Quantifier values at “x”can be applied to modify the non-Quantifier values at “x.” This isdepicted, in FIG. 2A, by step 203.

2.2. Pseudocode and Example

FIGS. 6A-6G present an example pseudocoded procedure(“sentence_classify”) for performing classification of a sentence. Inthis section, sentence_classify is presented along with an example inputsentence 1000 (FIG. 10A). The input to sentence_classify is a sentence“S” (FIG. 6A, line 2) and the output is a parse structure “T” (FIG. 6G,line 22) to which has been added classification information. Theclassification information returned can be specified as concept-valuepairs (discussed further below) that are associated with nodes of theparse structure. For each node of the output parse structure, itsconcept-value pairs, for non-Quantifier concepts, specify assertedconcepts of the input sentence “S.”

While the pseudocode presented herein describes application of aclassification process to a sentence, the process can be applied to anyother type of UNLD.

2.2.1. Parse

Sentence classification can begin by parsing the input sentence “S” toproduce a parse structure “T.” FIG. 6A, line 4. The level at which “S”is parsed can depend on the application. An example level is for eachparse structure node to represent a lexical unit. If the lexical unitlevel is utilized, parsing a sentence “S” involves segmenting “S” intoits lexical units and marking the part of speech for each lexical unit.The result of applying these processes, to the example input sentence ofFIG. 10A, is shown in FIGS. 10B and 10C. FIG. 10B depicts a table oflexical units and part-of-speech designations for the example inputsentence 1000 while FIG. 100 depicts an example parse structure.

2.2.2. Populate Parse Structure

The parse structure can be populated, with the concepts referenced bythe input sentence, as follows.

Each linguistic feature of “S” can be identified and collected in a listcalled “LF_list.” FIG. 6A, line 11. For the case where the pattern to bematched, for a linguistic feature to apply, is a lexical unit, thedetermination of each linguistic feature of “5” can be accomplished asfollows. Each lexical unit of “S” can be looked-up in a databasereferred to herein as a “concept feature database” (CFDB). An exampleCFDB is shown in FIG. 9A. As can be seen, for the example CFDB, eachrow, in the leftmost column, specifies a lexical unit pattern as alinguistic feature. The remaining columns of each row can specify one ormore “semantic units” (or SUs). The SUs specify the concepts that areregarded as referred-to if the linguistic feature of that row ismatched. It can be readily appreciated that, with sufficient rows in aCFDB and sufficient SUs per row, a CFDB can represent complete (orapproximately complete) concept feature sets for multiple pinnacleconcepts.

Each linguistic feature identified in “S” can be iterated over, with thecurrent linguistic feature referred to as “LF_curr.” FIG. 6A, lines12-26.

As can be seen in FIG. 6A, line 14, a list of SUs, “SU_list,” isdetermined for each value of LF_curr. Each SU of the SU_list is iteratedover. FIG. 6A, lines 18-25. In general, a semantic unit, for alinguistic feature “LF” identified in a UNLD “x,” can specify threeitems. First, the semantic unit can specify a pinnacle concept “C” thatis regarded as referred-to whenever “LF” is found in a UNLD.” Second,the semantic unit can indicate a sub-unit of “x” regarded asresponsible, at least in part, for the reference to “C.” Third, thesemantic unit can specify a reference level with which “C” isreferred-to.

The structure of each SU, for the example CFDB of FIG. 9A, is shown inFIG. 9B. As can be seen, the SU of FIG. 9B is comprised of three parts:a syntactic relationship label (SRL), a concept label (CL) and areference level indicator (RLI). The CL specifies the pinnacle concept“C” that is regarded as referred-to because of the presence of LF_currin input sentence “S”. The RLI specifies a reference level with which“C” is referred-to. The SRL specifies a part of sentence “S,” forexample a lexical unit of “S,” regarded as responsible, at least inpart, for the CL and RLI values being applicable to “S.”

FIG. 10D depicts the example parse structure of FIG. 10C, to which theconcept-value pairs, specified by the SUs, have been added. Each node ofthe parse structure corresponds to a lexical unit of the sentence to beclassified. Each concept-value pair, attached to a node, indicates apinnacle concept that is referred to by that node and the referencelevel of such referral. Thus, with respect to an SU, its SRL specifiesthe node, its CL specifies the concept of a concept-value pair and itsRLI specifies the value of a concept-value pair. This assignment ofconcept-value pairs is shown in the pseudocode of FIG. 6A at line 24.

For the parse structure FIG. 10D, we can see that only the followinglexical units match linguistic feature patterns in the CFDB of FIG. 9A:“solve,” “problem” and “with.” For example, the CFDB of FIG. 9A containsa row for the linguistic feature pattern “problem/n.” Pattern“problem/n” matches the lexical unit “problem” when its part of speechis noun (indicated by the “/n”). The SU for “problem” is “S B 0.7.” Ascan be seen in FIG. 9C, the SRL value “S” stands for “Self” which meansthat it is the linguistic feature that selected the SU that receives theRLI of that SU. As can be seen in FIG. 9D, the CL value “B” stands for“Bad.” Therefore, in the parse structure of FIG. 10D, at the node for“problem,” a concept-value pair is stored for “Bad” and 0.7.

Each concept-value pair, of the parse structure diagrams presentedherein, is represented as a circle that contains a letter for thepinnacle concept and a value for the reference level of that pinnacleconcept. Also, a circle composed of long dashes indicates concept-valuewhere the concept is of type non-Quantifier while a circle composed ofshort dashes indicates concept-value where the concept is of typeQuantifier.

Similar processing occurs for the linguistic feature patterns “solve/v”and “with/prep” of FIG. 9A. Pattern “solve/v” matches an occurrence ofthe lexical unit “solve” when its part of speech is verb (indicated bythe “/v”). Pattern “solve/v” has seven semantic units that are processedas follows (from left to right).

The SUs “S B 0.7” and “S G 0.75” specify that “solve” itself receive a“Bad” value of 0.7 and a “Good” value of 0.75. Therefore, in the parsestructure of FIG. 10D, at the node for “solve,” two concept-value pairsare stored: (“Bad,” 0.7) and (“Good,” 0.75).

The SUs “A B 0.7” and “A G 0.75” specify, respectively, that the Agentof “solve” receive a “Bad” value of 0.7 and a “Good” value of 0.75. Theagent of “solve” is determined from the parse structure information ofFIG. 10D. As can be seen from FIG. 10D, the agent of “solve” is “using.”Therefore, in the parse structure of FIG. 10D, at the node for “using,”two concept-value pairs are stored: (“Bad,” 0.7) and (“Good,” 0.75).

The SUs “P B 0.7” and “P G 0.75” specify, respectively, that the Patientof “solve” receive a “Bad” value of 0.7 and a “Good” value of 0.75. Thepatient of “solve” is determined from the parse structure information ofFIG. 10D. As can be seen from FIG. 10D, the patient of “solve” is“problem.” Therefore, in the parse structure of FIG. 10D, at the nodefor “problem,” two concept-value pairs are stored: (“Bad,” 0.7) and(“Good,” 0.75).

SU “P S 0.7” specifies that the Patient of “solve” receive a “Solution”value of 0.7. Therefore, in the parse structure of FIG. 10D, at the nodefor “problem,” the following concept-value pair is stored: (“Solution,”0.7).

Linguistic feature pattern “with/prep” has one SU that is processed asfollows. SU “O+0.7” specifies that the Object of “with” receive an“Intensify” value of 0.7. According to the parse structure of FIG. 10D,the object of with is “voltage.” Therefore, in the parse structure ofFIG. 10D, at the node for “voltage,” the following concept-value pair isstored: (“Intensify,” 0.7).

2.2.3. Quantifier Propagation

Those concept-value pairs of “T,” where the concept is of typeQuantifier, can be propagated through “T” as follows. This step ofpropagation is invoked in the pseudocode at FIG. 6B, line 10. Three mainrules, for Quantifier propagation, are shown in the pseudocode commentsof FIG. 6B at lines 1-9.

The first rule is that the propagations, of each concept-value pair, arekept separate. This can be accomplished by assigning a unique identifierto each concept-value pair. For example, suppose a concept-value pair“p” is assigned a unique identifier “id1.” When “p” propagated, thoseadditional copies of “p” can all be assigned “id1.” In this way, whenpropagation is complete, all concept-value pairs, that resultedoriginally from “p,” can be identified by the fact that their uniqueidentifier is “id1.”

The second rule is as follows. A concept-value pair, at a particularparse structure node “n,” can only propagate to another node “x” ifthere is an edge from “n” to “x” and that edge is one of three types:“x” represents a verb “v” and “n” is the agent of “v;” “x” represents averb “v” and “n” is the patient of “v;” or “n” represents a modifier and“x” is what “n” modifies. The principle behind the second rule is asfollows: propagate a concept-value pair, at a parse structure node “n,”to another node “x” only if “x”,” relative to “n,” serves a more centralrole in the semantics of the sentence.

Each time a concept-value pair “p” arrives at a node “g,” from which “p”can propagate no further, the node “g” is called a “governing” node ofthe sentence. The collection of Quantifiers, at governing nodes,produces centralized locations where the Quantifiers can more fullyinteract with each other. Therefore, at governing nodes, the net effectof Quantifiers can be applied to the non-Quantifiers. An example, of howthe “Negation” Quantifiers arising in a sentence can interact atgoverning nodes, is presented in section 5.4 (“Example NegationPropagation”).

The third rule is that if a concept-value pair does propagate from aparse structure node “n” to another node “x,” “x” receives a copy of thesame RLI value as “n” (i.e., no attenuation or amplification is appliedto the propagated value).

Once Quantifier propagation has been completed, any Quantifierconcept-value pair, at a non-governing node, is deleted (see pseudocodeof FIG. 6B, lines 13 to 18).

For the example of FIG. 10, a full propagation, of the Quantifierconcept-value pairs, is shown in FIG. 10E. As can be seen, the onlydifference, between FIGS. 10D and 10E, is that a copy of (“Solution,”0.7) has been propagated from “problem” to “solves.” For FIG. 10E,“solves” and “voltage” are governing nodes. The node “solves” is agoverning node because the concept-value pair at “problem” couldpropagate no further once it reached “solves.” The node “voltage” is agoverning node because the concept-value pair at “voltage” could notpropagate from “voltage.” FIG. 10E also indicates that the concept-valuepair at “problem” is to be deleted since “problem” is a non-governingnode.

2.2.4. Determine Quantifier Values

Once the Quantifier concept-value pairs have been fully propagated, thedetermination of the set of final Quantifier concept-value pairs, thatwill be used to modify any non-Quantifier concept-value pairs at eachnode “n,” can be accomplished as follows. In order to explain thisprocess, it is helpful to divide the set of Quantifier concepts into twoparts: those that do not perform any type of negation (the non-negationQuantifiers) and those that do perform some type of negation (thenegation Quantifiers). An example division of Quantifier concepts, intothe negation and non-negation types, is indicated by the column“Quantifier Type” of FIG. 9E.

2.2.4.1. Non-Negation Quantifiers

2.2.4.1.1. Sum Values On Per-Concept Basis

The following can then be performed at each governing node “n.” For eachnon-negation Quantifier, “Non_Neg_Q,” that is represented at “n” by aset “s” of two or more concept-value pairs, replace “s” with a singleconcept-value pair where the concept is “Non_Neg_Q” and the value is thesum of the values from the pairs of “s.”

This process is illustrated, in more detail, in FIG. 6B, lines 21-30.The first (outermost) loop, that begins at line 21, iterates over eachgoverning node “n” of parse structure “T.” The second loop, that beginsat line 22, iterates over each type of non-negation Quantifier for whichthere is one or more concept-value pairs at “n.” Example types ofnon-negation Quantifiers, for iteration over, include those listed inFIG. 9E with the value “Non-Negation” in the “Quantifier Type” column.The third (innermost) loop, that begins at line 24, iterates over eachconcept-value pair, at node “n,” where the concept is of the typespecified by the second loop. Each concept-value pair, iterated over bythe third loop, is referred to as “NNQ_cvp.” Each “NNQ_cvp” is removedfrom node “n” (line 26). The sum of the value portion, of allconcept-value pairs “NNQ_cvp,” is accumulated as “sum1” (line 25). Oncethe third loop finishes, a concept-value pair is added to node “n” wherethe concept portion is determined by the current value of “NNQ_type” andthe value portion is determined by the value of “sum1” (line 28).

Since the example of FIG. 10E does not illustrate this situation,consider the following example that shall be referred to herein as“Example 1.” Example 1 supposes that the concept-value pairs at agoverning node “n” are the following: (“Intensify,” 0.7), (“Intensify,”0.5), (“Increase,” 0.7), (“Solution,” 0.7), (“Solution,” 0.5),(“Negation,” 0.6), (“Good,” 0.3), (“Bad,” 0.6). Since there are twoconcept-value pairs with the same non-negation Quantifier (i.e.,“Intensify”), they are replaced with a single concept-value pair whoseconcept is still “Intensify” but whose value is the sum of 0.7 and 0.5.Therefore, the resulting concept-value pairs at a node “n” are thefollowing: (“Intensify,” 1.2), (“Increase,” 0.7), (“Solution,” 0.7),(“Solution,” 0.5), (“Negation,” 0.6), (“Good,” 0.3), (“Bad,” 0.6).

2.2.4.1.2. Apply PLQ

The value portion “v,” of each non-negation Quantifier concept-valuepair, can be converted into a value, suitable for modifyingnon-Quantifier values, as follows. The value “v” can be used as anexponent (or “power”) of a base value “b,” where the base value isdetermined by the type of the Quantifier. This use of exponentiation isreferred to as application of the “Power Law for Quantifiers” (PLQ).

This process is illustrated, in more detail, in FIG. 6C, lines 1-9. Thefirst (outermost) loop, that begins at line 2, iterates over eachgoverning node “n” of parse structure “T.” The second (innermost) loop,that begins at line 3, iterates over each concept-value pair, at node“n,” where there is only one concept-value pair, for each non-negationQuantifier concept type, because of the previous action of summing likeconcept-value pairs. Each concept-value pair, iterated over by thesecond loop, is referred to as “NNQ_cvp.” The variable “exponent” is setto the value portion of NNQ_cvp (line 4). The variable “base” is set tothe value dependent upon the type of non-negation Quantifier conceptspecified by the concept portion of NNQ_cvp (line 5). The new value, forthe value portion of NNQ_cvp, is found by raising the value of “base” tothe power determined by “exponent” (line 6). This new value thenreplaces the current value for NNQ_cvp (line 7).

An example mapping, from Quantifier type to base value, is shown in FIG.9E. As can be seen from FIG. 9E, “Intensify” is treated, for purposes ofPLQ calculation, just like an “Increase” operator. The distinction, indefinition, between “Intensify” and “Increase” is not used herein.“Intensify” is defined to mean something more than the default value(e.g., the word “very” does this). “Increase” implies a time componentto becoming more than the default value. “Diminish” and “Decrease” havean analogous relationship.

In the example of FIG. 10E, it can be seen that the only non-negationQuantifier concept-value pair is the one at the node for “voltage” wherethe pinnacle concept is “Intensify.” From FIG. 9E, it can be determinedthat the base value “b” for “Intensify” is 1.25. In accordance with PLQ,the value of 0.7, at the node for voltage, is used as an exponent for1.25 to produce the value 1.17. FIG. 10F is the same as FIG. 10E, exceptthat PLQ has been applied to the concept-value pair of the “voltage”node.

For Example 1, application of PLQ produces the following result:(“Intensify,” 1.31), (“Increase,” 1.17), (“Solution,” 0.7), (“Solution,”0.5), (“Negation,” 0.6), (“Good,” 0.3), (“Bad,” 0.6).

2.2.4.2. Negation Quantifiers

2.2.4.2.1. Thresholding

The negation Quantifiers, at a governing node “n,” can be converted, asfollows, into a form suitable for scaling the non-Quantifierconcept-value pairs at “n.” The value portion, of each negationQuantifier concept-value pair at node “n,” is thresholded to either 0or 1. This step is shown in the pseudocode at FIG. 6C, lines 11-18. Thethreshold, which an indication of negation must be stronger than to becounted as a negation for purposes of modifying non-Quantifiers, dependsupon the particular application. An example threshold is 0.4.

In the example of FIG. 10F, there is one negation Quantifierconcept-value pair at a governing node: the concept-value pair at the“solves” node. FIG. 10G is the same as FIG. 10F, except that a thresholdof 0.4 has been applied to this negation Quantifier concept-value pair.Application of the threshold to Example 1 results in the following:(“Intensify,” 1.31), (“Increase,” 1.17), (“Solution,” 1.00),(“Solution,” 1.00), (“Negation,” 1.00), (“Good,” 0.3), (“Bad,” 0.6).

2.2.4.2.2. Sum Values On Per-Concept Basis

The following can then be performed at each governing node “n.” For eachtype of negation Quantifier, “Neg_Q,” that is represented at “n” by aset “s” of two or more concept-value pairs, replace “s” with a singleconcept-value pair where the concept is “Neg_Q” and the value is the sumof the values from the pairs of “s.”

This process is illustrated, in more detail, in FIG. 6C, lines 20-31.The first (outermost) loop, that begins at line 21, iterates over eachgoverning node “n” of parse structure “T.” The second loop, that beginsat line 22, iterates over each type of negation Quantifier for whichthere is one or more concept-value pairs at “n.” Example types ofnegation Quantifiers, for iteration over, include “Negation” and“Solution” of FIG. 9E. The third (innermost) loop, that begins at line24, iterates over each concept-value pair, at node “n,” where theconcept is of the type specified by the second loop. Each concept-valuepair, iterated over by the third loop, is referred to as “NQ_cvp.” Thevalue portion of each NQ_cvp is extracted (line 25) and accumulated(line 26). Each “NQ_cvp” is removed from node “n” (line 27). Once thethird loop finishes, a concept-value pair is added to node “n” where theconcept portion is determined by the current value of “NQ_type” and thevalue portion is determined by the value of “sum1.”

Since there is only one negation Quantifier concept-value pair at anynode in FIG. 10G, the above-described step does not change FIG. 10G.However, application of the above-described step to Example 1 results inthe following: (“Intensify,” 1.31), (“Increase,” 1.17), (“Solution,”2.00), (“Negation,” 1.00), (“Good,” 0.3), (“Bad,” 0.6).

2.2.4.2.3. Apply PLQ

The value portion “v,” of each negation Quantifier concept-value pair,can be converted into a value, suitable for modifying non-Quantifiervalues, as follows. As with the non-negation Quantifier concept-valuepairs, an example way to accomplish this conversion is to use the PowerLaw for Quantifiers: the value “v” can be used as an exponent (or“power”) of a base value “b,” where the base value is determined by thetype of the Quantifier. The base value is typically −1 so that an evennumber of negation Quantifiers produces +1 (that will not change thenon-Quantifiers to which it is applied) and an odd number of negationQuantifiers produces −1 (that can “flip” the non-Quantifier, to which itis applied, to its correlative concept). An example mapping, fromnegation Quantifier type to base value, is shown in FIG. 9E.

This process is illustrated, in more detail, in FIG. 6D, lines 1-9. Thefirst (outermost) loop, that begins at line 2, iterates over eachgoverning node “n” of parse structure “T.” The second (innermost) loop,that begins at line 3, iterates over each negation Quantifierconcept-value pair, at node “n,” where there is only one concept-valuepair for each negation Quantifier concept type because of the previousaction of summing like concept-value pairs. Each concept-value pair,iterated over by the second loop, is referred to as “NQ_cvp.” Thevariable “exponent” is set to the value portion of NQ_cvp (line 4). Thevariable “base” is set to the value dependent upon the type of negationQuantifier concept specified by the concept portion of NQ_cvp (line 5).The new value, for the value portion of NQ_cvp, is found by raising thevalue of “base” to the power determined by “exponent” (line 6). This newvalue then replaces the current value for NQ_cvp (line 7).

In the example of FIG. 10G, it can be seen that there is one negationQuantifier concept-value pair: the pair at the node for “solves.” Forthis concept-value pair, the negation Quantifier is of type “Solution.”From FIG. 9E, it can be determined that the base value “b” for“Solution” is −1. In accordance with the Power Law for Quantifiers, thevalue of 1.0, at the node for “solves,” is used as an exponent for −1 toproduce the value −1. FIG. 10H is the same as FIG. 10G, except that thePower Law of Quantifiers has been applied to the concept-value pair ofthe “solves” node. For Example 1, the double negative for “Solution” andsingle negative for “Negation” produce, respectively, values of +1 and−1. Example 1 results in the following: (“Intensify,” 1.31),(“Increase,” 1.17), (“Solution,” 1.00), (“Negation,”-1.00), (“Good,”0.3), (“Bad,” 0.6).

2.2.5. Quantifier Back Propagation

Back propagation allows the net effect of Quantifiers, whose net effectwas able to be determined because of central collection at governingnodes, to be applied at all relevant nodes with non-Quantifiers.

Each concept-value pair of “T,” where the concept is of type Quantifier,can be back propagated through “T” as follows. The step of backpropagation is invoked in the pseudocode at FIG. 6D, line 21. Three mainrules, for Quantifier back propagation, are shown in the pseudocodecomments of FIG. 6D at lines 12-20. This step is called “back”propagation because it is, essentially, the reverse of the Quantifierpropagation described above (see section 2.2.3 “QuantifierPropagation”).

The first rule, of Quantifier back propagation, is that the same as thefirst rule of Quantifier propagation: the propagations of eachconcept-value pair are kept separate.

The second rule, of Quantifier back propagation, is essentially areversal of the second rule of Quantifier propagation. A concept-valuepair, at a particular parse structure node “n,” can only propagate toanother node “x” if there is an edge from “n” to “x” and that edge isone of three types: “n” represents a verb “v” and “x” is the agent of“v;” “n” represents a verb “v” and “x” is the patient of “v;” or “x”represents a modifier and “n” is what “x” modifies. The principle behindthe second rule is as follows: propagate each concept-value pair, at agoverning node “n,” to each other node “x” that is governed by “n.” Thedefinition of “governing” node is presented above (see section 2.2.3“Quantifier Propagation”).

The third rule is that if a concept-value pair does propagate from aparse structure node “n” to another node “x,” “x” receives a copy of thesame RLI value as “n” (i.e., no attenuation or amplification is appliedto the propagated value).

For the example of FIG. 10H, a back propagation, of the Quantifierconcept-value pairs, proceeds as follows. In FIG. 10I, the concept-valuepair for “Solution” is given the unique identifier 1050 and theconcept-value pair for “Intensify” is given the unique identifier 1051.In FIG. 10J, concept-value pairs 1050 and 1051 have been fully backpropagated.

2.2.6. Scale Non-Quantifier Values with Quantifier Values

For each node, the Quantifier values can be used to scale thecorresponding non-Quantifier values. This operation is described in thepseudocode of FIG. 6E, line 1 to 6F, line 30. Each scaled non-Quantifiervalue is referred to herein as a “derived non-Quantifier value” or DNV.

The determination of DNVs is a two-part process for each node. The firstpart is the determination of the scaling factors. A scaling factor canbe a product of the value portions of Quantifier concept-value pairs. Ifa node has no Quantifier concept-value pairs, the default scaling factoris 1.0.

Two scaling factors are determined in FIG. 6E at lines 4-14. The firstscaling factor (referred to in the pseudocode as“solution_scaling_factor”) includes the value (if any) for theQuantifier “Solution.” The pseudocode presents this determination atlines 4-8. “Solution” differs from “Negation” as follows: “Solution” canonly “flip” (or invert) a reference to “Bad” into a reference to “Good,”while “Negation” can invert any non-Quantifier concept into itscorrelative concept. The second scaling factor (referred to in thepseudocode as “general_scaling_factor”) does not include the value (ifany) for the Quantifier “Solution.” The pseudocode presents thisdetermination at lines 10-14.

The second part, of the DNV determination process, is the scaling, bythe appropriate scaling factor, of the value portion of eachnon-Quantifier concept-value pair at a node “n.” Since “Solution” onlyapplies to “Bad,” the “solution_scaling_factor” is only applied to thoseconcept-value pairs where the concept is “Bad.” For all otherconcept-value pairs, other than “Bad,” the general_scaling_factor isapplied.

If the scaling factor is a negative number (which will happen wheneveran odd number of negations are determined to apply to the unitrepresented by a parse structure node), scaling of a non-Quantifierconcept-value pair “NQ_cvp” can be handled as follows, so long as theconcept “C,” of “NQ_cvp,” has a correlative concept that we shall referto as “−C.” Assume “NQ_cvp” has a scaling factor s, where s is set to“solution_scaling_factor” if “C” is “Bad” or s is otherwise set to“general_scaling_factor.” Further assume that the magnitude of the valueportion of “NQ_cvp” is “m.” The absolute value of the product s×mbecomes the scaled value for “NQ_cvp,” but the concept is changed from“C” to “−C.” Other than for the concepts “Good” and “Bad,” if there is apre-existing concept-value pair “corr_NQ_cvp” for “−C,” its valueportion is also scaled by s and its concept is inverted from “−C” to“C.”

If, however, “C” is “Good” or “Bad,” and if there is a pre-existingconcept-value pair “corr_NQ_cvp” for “−C,” its scaling factor “s_corr”may be a positive number. In this case, as a result of scaling, “NQ_cvp”and “corr_NQ_cvp” can end-up representing the same concept “−C.” Thissituation is handled by only keeping the concept-value pair with thelarger scaled value.

Regardless of whether the scaling value is negative or not, the resultof scaling can be to set the value, of a non-Quantifier concept-valuepair, to a value greater than a maximum permissible value (e.g., greaterthan 1.0). In this case, the value can be replaced with exactly themaximum permissible value (e.g., 1.0).

The scaling process is described in more detail in the pseudocode ofFIG. 6F at lines 1-29. The process operates as follows.

Each concept-value pair “NQ_cvp” is iterated over (line 1).

If the concept of “NQ_cvp” is “Bad,” the scaling factor “scaling_factor”is set to “solution_scaling_factor” and is otherwise set to“general_scaling_factor” (lines 3-6).

The value portion of each pair is extracted (line 8), scaled (line 9)and replaces the pre-scaled value of “NQ_cvp” (line 10).

If the value portion of NQ_cvp is greater than or equal to zero, thescaling process is complete (except for, possibly, limiting the scaledvalue to be less than or equal to a maximum value).

If, however, the value portion of NQ_cvp is less than zero (tested forby line 12), the following steps can be taken. The value portion ofNQ_cvp is replaced with its absolute value (line 13) and the conceptportion of NQ_cvp is changed to indicate the correlative concept (line14). As long as the concept of NQ_cvp is not “Good” or “Bad” these stepsare sufficient since if there is a pre-existing concept-value pair forthe correlative concept, when it is iterated over (by the loop of line1) its concept will also be inverted.

The “if” of lines 16-17 tests whether the concept of “NQ_cvp” is “Good”or “Bad” and if the scaling factor for the correlative concept is of anopposite sign. If this test is satisfied it is known that if there is apre-existing concept-value pair (referred to as “pe_NQ_cvp”) for thecorrelative concept, when it is iterated over (by the loop of line 1)its concept will not be inverted. This results in two concept-valuepairs for the same concept. This is handled by keeping only theconcept-value pair whose value portion is greater (lines 23-26).

FIG. 10K shows the result of scaling the non-Quantifier values of FIG.10J. As can be seen, for nodes “using,” “solves” and “problem,” theQuantifier “Solution” converts each non-Quantifier “Bad” to thenon-Quantifier “Good” with the same value of 0.7.

Example 1 was last determined to consist of the following concept-valuepairs: (“Intensify,” 1.31), (“Increase,” 1.17), (“Solution,” 1.00),(“Negation,”-1.00), (“Good,” 0.3), (“Bad,” 0.6). Because “Solution” hasthe value 1.00, the scaling factor, with or without solution, is thesame: 1.31×1.17×−1.00=−1.53. Example 1, after scaling its non-Quantifierconcept-value pairs by 1.53, is as follows: (“Intensify,” 1.31),(“Increase,” 1.17), (“Solution,” 1.00), (“Negation,”-1.00), (“Bad,”0.46), (“Good,” 0.92).

2.2.7. Propagate Non-Quantifiers

Non-Quantifier value propagation is invoked in the pseudocode at FIG. 6Gat line 8. The rules for non-Quantifier value propagation are shown inthe pseudocode comments of FIG. 6G at lines 1-7. As can be seen, thereare three main rules.

The first rule is that the propagations, of each non-Quantifierconcept-value pair, are kept separate.

The second rule is as follows. A concept-value pair, at a particularparse structure node “n,” can propagate to another node “x” so long asthere is an edge from “n” to “x;” the type of edge, from “n” to “x,”does not matter. The general principle, behind the second rule, is asfollows. When part of a sentence has been determined to refer to anon-Quantifier because it is recognized as a linguistic feature, therest of the sentence is regarded as also referring, to some degree, tothat non-Quantifier.

The third rule is as follows. If a non-Quantifier concept-value pairdoes propagate, from a parse structure node “n” to another node “x,” “x”receives a copy, of the concept-value pair, where the value portion hasbeen attenuated. An example way of achieving attenuation is to multiplythe value portion, of the concept-value pair for “n,” by an attenuationcoefficient. The attenuation coefficient will have a value less than1.0. The general principle, behind the third rule, is as follows. Therest of a sentence, relative to a linguistic feature that caused anon-Quantifier to be initially recognized, is regarded as referring tothat Quantifier to a degree inversely proportional to its distance fromthe linguistic feature.

Continuing with Example 1, assume that non-Quantifier propagation addsnon-Quantifier concept-value pairs, to the node represented by Example1, as follows: (“Intensify,” 1.31), (“Increase,” 1.17), (“Solution,”1.00), (“Negation,”-1.00), (“Good,” 0.3), (“Good,” 0.92), (“Bad,” 0.46).

2.2.8. Select Maximum Non-Quantifiers

Once the non-Quantifier concept-value pairs have been fully propagated,the determination of the set of final non-Quantifier concept-valuepairs, at each node “n,” can be accomplished as follows.

The following can then be performed at each node “n.” For each type ofnon-Quantifier, “Non_Q,” that is represented at “n” by a set “s” of twoor more concept-value pairs, replace “s” with a single concept-valuepair where the concept is “Non_Q” and the value is the maximum of thevalues from the pairs of “s.”

This process is illustrated, in more detail, in FIG. 6G, lines 10-20.The first (outermost) loop, that begins at line 11, iterates over eachnode “n” of parse structure “T.” The second loop, that begins at line12, iterates over each type of non-Quantifier for which there is one ormore concept-value pairs at “n.” Example types of non-Quantifiers, foriteration over, include “Good” and “Bad” of FIG. 9D. The third(innermost) loop, that begins at line 14, iterates over eachconcept-value pair, at node “n,” where the concept is of the typespecified by the second loop. Each concept-value pair, iterated over bythe third loop, is referred to as “NQ_cvp.” Each “NQ_cvp” is removedfrom node “n” (line 16). The maximum value portion, of all concept-valuepairs “NQ_cvp,” is accumulated as “max1” (line 15). The function“find_max,” of line 15, is defined to return the maximum value of itstwo arguments: the current value of “max1” and the value portion of“NQ_cvp.” Once the third loop finishes, a concept-value pair is added tonode “n” where the concept portion is determined by the current value of“NQ_type” and the value portion is determined by the value of “max1”(line 18).

FIG. 10L depicts the result of both (i) propagating the non-Quantifierconcept-value pairs of FIG. 10K and (ii) selecting, for each nodenon-Quantifier concept represented at each node, the singleconcept-value pair with the greatest value. FIG. 10L is based upon usingan attenuation coefficient of 0.9, and rounding each application of theattenuation coefficient to two decimal places, when propagating thenon-Quantifier concept-value pairs of FIG. 10K. Continuing with Example1, selecting the maximum produces the following: (“Intensify,” 1.31),(“Increase,” 1.17), (“Solution,” 1.00), (“Negation,”-1.00), (“Good,”0.92), (“Bad,” 0.46).

2.2.9. Summary

The general structure of the process, presented in section 2.2(“Pseudocode and Example”) through the pseudocode, is summarized by FIG.2B.

The step of parsing, described above in section 2.2.1 (“Parse”), isrepresented in FIG. 2B by step 210.

The step of parse structure population, described above in section 2.2.2(“Populate Parse Structure”), is represented in FIG. 2B by step 211.

Once parse structure “T” has had concept-value pairs assigned to it inaccordance with step 211 of FIG. 2B, there are three main process“tracks” that can be performed. The first track, represented in FIG. 2Bby the column of steps 220-222, relates to processing thoseconcept-value pairs where the concept is of type non-negationQuantifier. The second track, represented in FIG. 2B by the column ofsteps 230-234, relates to processing those concept-value pairs where theconcept is of type negation Quantifier. The third track, represented inFIG. 2B by the column of steps 240-242, relates to processing thoseconcept-value pairs where the concept is of type non-Quantifier. As canbe seen, the first and second tracks can proceed, at least to a certainextent, independently of each other. The first track can proceed tocompletion, at step 222, independently of the state of the second track.The second track can proceed to completion, at step 234, independentlyof the state of the second track.

The first track operates as follows. Step 220 propagates through “T”those concept-value pairs where the concept is a non-negationQuantifier. This step is addressed in above section 2.2.3 (“QuantifierPropagation”). Step 221 applies when, for each node of “T,” there aretwo or more concept-value pairs that relate to a single non-negationQuantifier. An approach to combining concept-value pairs, that share acommon concept, is described in above section 2.2.4.1.1 (“Sum Values OnPer-Concept Basis”). Step 222 applies a function, to each concept-valuepair at a node, to transform the value portion of each into a valueappropriate for scaling other concept-value pairs. An example function,called the “Power Law for Quantifiers” is described in above section2.2.4.1.2 (“Apply PLQ”).

The second track operates as follows. Step 230 propagates through “T”those concept-value pairs where the concept is a negation Quantifier.This step is addressed in above section 2.2.3 (“QuantifierPropagation”). Prior to combining concept-value pairs that share acommon negation Quantifier concept (step 233), each such pair canthresholded (by step 232). An approach to the thresholding of step 232is described in above section 2.2.4.2.1 (“Thresholding”).

Step 233 applies when, for each node of “T,” there are two or moreconcept-value pairs that relate to a single negation Quantifier. Anapproach to combining concept-value pairs, that share a common concept,is described in above section 2.2.4.2.2 (“Sum Values On Per-ConceptBasis”).

Step 234 applies a function, to each concept-value pair at a node, totransform the value portion of each into a value appropriate for scalingother concept-value pairs. An example function, called the “Power Lawfor Quantifiers” is described in above section 2.2.4.2.3 (“Apply PLO”).

The Quantifier values produced by steps 222 and 234 can be backpropagated (step 235) such that all relevant nodes, with non-Quantifiervalues, can have their non-Quantifier values scaled (at step 240). Backpropagation is addressed in above section 2.2.5 (“Quantifier BackPropagation”) and scaling is addressed in above section 2.2.6 (“ScaleNon-Quantifier Values With Quantifier Values”).

Step 241 propagates through “T” those concept-value pairs where theconcept is a non-Quantifier. This step is addressed in above section2.2.7 (“Propagate Non-Quantifiers”). Step 242 applies when, for eachnode of “T,” there are two or more concept-value pairs that relate to asingle non-Quantifier. An approach to combining concept-value pairs,that share a common concept, is described in above section 2.2.8(“Select Maximum Non-Quantifiers”).

3. CONCEPT-BASED AND KEYWORD-BASED SEARCH, PSEUDOCODE

The pseudocode presented in this section describes a combinedconcept-based and keyword-based search system. It is organized intothree main phases: indexing (FIG. 4), query accepting (FIG. 5A) andkeyword-based searching (FIG. 5B). A discussion of a productionenvironment computer system, for executing these phases, is described insection 5.3 (“Production Environment”).

Phase 1 (indexing) can be performed independent of whether a user hasrequested a search. Since indexing can be performed on a large body ofdata, and can require periodic updating, it can be appropriate toexecute such procedures on separate computing hardware from that whichresponds to user queries. Indexing can also be performed, for example,at times (e.g., at night or on weekends) when searches are not beingrun.

Keyword-searching (phase 3) happens in response to entry of a user queryduring query-accepting (phase 2).

3.1. Indexing

As discussed above, any type of computer-accessible content can serve asinput to the indexing phase, so long as the input data represents acollection of natural language discourse. This section presents, forpurposes of example, a database (i.e., the “input database”) as thesource of data to be indexed.

An example input database is discussed above in Section 1.3.1 (“New UsesFor An Existing Technology”).

The output of phase 1 is one or more Concept-Based DBs (CBDBs). Forexample the CBDBs produced can include CBDB(“Good”) and CBDB(“Bad”).

Each document, of the input database, is iterated over. FIG. 4, line 1.

Each sentence, within each document, is iterated over. FIG. 4, line 2.

Each sentence is parsed and classified according to which pinnacleconcepts it asserts. FIG. 4, line 7. This parsing and classification canbe accomplished in accordance with the procedure “sentence_classify”that was described in above section 2 (“Concept-Based Classification”).The results returned (referred to as “result_parse”), from parsing andclassification, can be in any suitable form. A suitable form is as aparse structure, where each node is representative of a structural unitof the input sentence. A suitable level of structural representation,for each node of the parse structure, can be to represent a lexical unitof the input sentence.

Each pinnacle concept, that is to be the organizing concept for a CBDB,is iterated over. FIG. 4, line 12.

Each node of result_parse can be accessed for a reference level withwhich it asserts the current pinnacle concept (“PC_curr”) at issue (line14). This is accomplished by iterating over each node of result_parse(see line 13) and by accessing each node by the current pinnacle conceptPC_curr. This accessing can be accomplished by finding the concept-valuepair, at node NU_curr and for concept PC_curr, and retrieving the“value” portion of that concept-value pair.

If, for PC_curr, the reference level value of NU_curr is above a certainpredetermined threshold (see line 15), then a snippet (“snippet_curr”)is formed (see line 18) that includes S_curr. “snippet_curr” is added tothe appropriate CBDB, and it is indexed for later keyword-basedsearching (see line 28).

As an efficiency measure, for a later “ranking” phase, classificationresults can be stored with the newly-formed snippet (i.e.,“snippet_curr”). FIG. 4, lines 25-26. Specifically, for each sentence“s” that forms snippet_curr, its parse and classification results (i.e.,the result of applying “sentence_classify” to “5”) can be stored withit. For the sentence of snippet_curr that corresponds to S_curr, thisinvolves storing with such sentence a copy of results_parse. For eachother sentence “s,” of which snippet_curr is formed, it is assumed(according to processes not illustrated in the pseudocode) that itsparse and classification results are available for caching withsnippet_curr (any suitable scheme, for making such parse andclassification results available, can be used).

3.2. Query Accepting

In the query accepting phase, the user selects a CBDB to be searched(FIG. 5A, line 5) and enters a keyword-based search (FIG. 5A, line 7)for that CBDB. The CBDB selected is referred to, in the pseudocode, as“CBDB_curr.” The keyword-based search is referred to, in the pseudocode,as the current Input Query (or “IQ_curr”).

3.2.1. Query Form

While any known form of keyword-based query can be used, an examplehierarchical form, for IQ_curr, is presented in this section. The queryform presented in this section has been found to be a particularlyuseful way to express queries for the search of a concept-based database(CBDB).

The largest unit, within IQ_curr, can be referred to as a “page.” Eachpage is related to any other pages of IQ_curr by a logical OR, meaningthat a snippet, of CBDB_curr, can satisfy IQ_curr if it satisfies anycombination of one or more pages.

Each page can be comprised of one or more query terms. Each query termcan be comprised of two parts: a keyword-specification and a requirementstatus.

The keyword-specification specifies one or more keywords that are to besearched for in each snippet. The keywords, of a keyword-specification,acts together according to a logical OR: a snippet can satisfy a queryterm so long as the snippet contains any combination of one or more ofthe keywords. The keywords, of a keyword-specification, can be separatedby commas.

Possible values, for the requirement status portion of a query term,are: Required, Optional, or Excluded. “Required” means that, in orderfor a snippet to satisfy a page, such snippet must satisfy all queryterms with a “Required” requirement status. “Optional” means that, inorder for a snippet to satisfy a page, such snippet need not satisfy anyquery terms with an “Optional” requirement status. However, during aranking phase, of the keyword-based search results, satisfaction ofOptional query terms can increase the ranking of a snippet in the searchresults. “Excluded” means that, in order for a snippet to satisfy apage, such snippet must not satisfy any query terms with an “Excluded”requirement status.

3.2.2. Page Usage Techniques

A page “p” is generally written such that any snippet “s,” thatsatisfies “p,” is likely to be of interest to the user for his or herparticular search topic. Further, within a satisfied page “p,” the morequery terms that are satisfied, the more likely “s” is to be of interestto the user.

When searching for new uses of an existing technology (which can also becalled the seeking of “out-licensing” opportunities), each snippet “s,”that satisfies at least one page of the search query, can becharacterized as describing a “problem,” or an “application” situation,for which the existing technology is likely to be useful.

When searching for a technology to address an existing problem (whichcan also be called the seeking of “in-licensing” opportunities), eachsnippet “s,” that satisfies at least one page of the search query, canbe characterized as describing a “benefit,” or a “solution,” that islikely to be useful in addressing the existing problem.

3.2.3. Example Query

FIG. 8A depicts an example query IQ_curr where the searcher has anexisting technology, for making batteries last longer, and would like tofind potential licensees.

As discussed above, in section 1.3.1 (“New Uses For An ExistingTechnology”), for this type of search topic, it is appropriate to searchCBDB(“Bad”) since one who is having some kind of problem is likely to beinterested in purchasing a solution to that problem.

An appropriate keyword-based search, of CBDB(“Bad”), can limit thesnippets retrieved to ones that address problems with batteries. FIG. 8Adepicts a single example search page 800 that is comprised of queryterms 810 to 813. As can be seen, query terms 810 to 812 are required,while query term 813 is optional.

Query term 810 requires any retrieved snippet to mention either“electricity” or the word “battery” as a noun (indicated by the “//n”).Query term 811 requires any retrieved snippet to mention either “out ofpower” or the phrase “burn out” where “burn” is a verb (indicated by the“//v”). Query term 812 requires any retrieved snippet to mention “last”as a verb (indicated by the “//v”).

Query term 813 means that, among snippets that satisfy query terms 810to 812, those that also mention either “portable” or “hand-held” will beranked higher in the results presented to the user.

3.3. Keyword-Based Searching

Once a keyword-based query IQ_curr has been entered, a keyword search,of CBDB_curr, can be accomplished as follows (pseudocode for thisprocess is shown in FIG. 5B).

First, it may be necessary to convert IQ_curr into a format that can beprocessed by the application responsible for performing the keywordsearch. Any known application, that provides a keyword search capabilitycompatible with the type of data storage used for CBDB_curr, can beused. An example type of keyword search application is the searchengine. An example suitable keyword search engine is the open-sourceprogram “Lucene.” Lucene is provided by the Apache Software Foundation,Forest Hill, Md., U.S.A. A form of IQ_curr, that is suitable for inputto a keyword search application, can be referred to as IQ_curr_logical.Production of IQ_curr_logical is shown in the pseudocode at FIG. 5B,line 3.

Second, IQ_curr_logical is applied to a keyword search engine. FIG. 5B,line 7. A keyword search engine selects snippets, from CBDB_curr, thatmeet the logical requirements of the IQ_curr_logical (e.g., at least onefield is present for each required term, and no excluded fields arepresent).

In addition to selecting snippets that meet the logical requirements ofthe input query, a keyword search engine can also assign a score to eachsnippet (referred to herein as a “snippet_score”). The magnitude of eachscore can be proportional to how well a snippet meets the logicalrequirements. Scoring can accomplished with a formula that emphasizesprevalence (i.e., number of times a search term appears in snippet) ofthe search terms. In the pseudocode of FIG. 5B, the output of thekeyword search engine is called “logically_scored_snippets.”

Once each snippet has been assigned a snippet_score, the snippetsresulting from the keyword-based search can be ranked, and displayed tothe user, according to decreasing snippet_score value. FIG. 5B, line 10.To prevent the list of displayed snippets from being too long, it can betruncated at a predetermined maximum number of snippets (e.g., 5000).

The list of displayed snippets can be displayed to the user by anysuitable technique. The amount of text presented to a user, for eachsnippet of the displayed list, can vary depending upon the such factorsas: the number of snippets obtained and the amount of time a user wishesto spend considering each search result. For example, the user can bepresented with a list of the snippets themselves. For each snippet ofthe displayed list, a link to the document, from which the snippet wasproduced, can also be displayed. The user can read snippets of thedisplayed list and decide which are actually worthy of furtherinvestigation. For each snippet the user wishes to investigate further,the user can select the link to the document from which the snippet wasproduced.

Alternatively, rather than presenting the snippets themselves in thedisplayed list, a further condensation of each snippet can be generated(e.g., a representative “title” can be generated for each snippet) and alist of those condensations displayed to the user.

4. CONCEPT-BASED RANKING

4.1. Overview

The results of the keyword-based search of step 112, of FIG. 1B, can bebetter ranked, as part of step 113, through the use of concept-basedranking. In general, however, concept-based ranking can be applied tothe output of any type of search process. Concept-based ranking relieson the input query, of step 111, having pinnacle concept propertiesspecified for some of the keyword-based search terms.

For example, FIG. 8B depicts the same query of FIG. 8A, except that aconcept property has been added to each query term. Query term 821 (QT821) specifies that a match is preferred if it is to a part (orsub-unit) of a snippet that has been classified (e.g., by“sentence_classify”) as asserting the “Bad” concept. Similarly, QT 822specifies that a match is preferred if it is to a sub-unit of a snippetthat has been classified as referring to the “Good” concept. QT 820 andQT 823 specify that a match is given no preference based upon whatconcept the matching sub-unit of the snippet refers to.

An example procedure, for implementing concept-based ranking, ispresented in FIGS. 5C and 5D. This procedure can be accomplishedin-between the steps of applying a keyword search application (e.g.,line 7 of FIG. 5B) and the display of the scored snippets to the user(e.g., line 10 of FIG. 5B) as discussed above in section 3(“Concept-Based and Keyword-Based Search, Pseudocode”).

The overall structure of the procedure is as follows. Each snippet, ofthe keyword-based results, is iterated over (FIG. 5C, line 3) andassigned a score (“snippet_score” at line 14 of FIG. 5D) based oncorrespondence between concept properties of the input query and conceptproperties of each snippet that matches the query. The concept-basedcomponent, of snippet_score, is determined by calling a procedure called“query_score.” FIG. 5C, line 12. The other components, of snippet_score,can be based upon whether each snippet appears to be intended to be readby a human (rather than a computer). The procedures, for determiningwhether a snippet is intended to be read by a human, are referred to as“naturalness_score” (FIG. 5C, line 22) and“length_appropriateness_score” (FIG. 5D, line 10). These procedures aredescribed in the pseudocode comments (FIG. 5C, lines 14-20 and FIG. 5D,lines 1-8).

Prior to calling query_score, the snippet to be scored can be “mapped”according to which parts of the snippet assert which pinnacle concepts.Such classification information can already be cached with each snippetduring the indexing phase as described in section 3.1 (“Indexing”).Alternatively, such classification information can be determined duringthe concept-based ranking phase (see FIG. 5C, lines 7-10). Suchclassification information can be determined by invoking“sentence_classify” on each sentence of each snippet. As discussed abovein section 2 (“Concept-Based Classification”), sentence_classifyreceives a sentence “S_curr” as input and returns a parse structurewhose nodes are coded with pinnacle concept-value pairs. The level ofsentence structural information represented by each node can be, forexample, a lexical unit. Each pinnacle concept-value pair “p” specifiesa reference level with which a pinnacle concept (indicated by “p”) isasserted by, at least, the sub-unit of S_curr represented by the node towhich “p” is attached.

4.2. Scoring a Snippet Relative to a Query

An example operation of query_score is depicted in the pseudocode ofFIGS. 7A and 7B. The query_score of FIGS. 7A and 7B depictsconcept-based snippet scoring where the input query, against which thesnippet to be score matched, is comprised of a single page of queryterms. An example, single page, query is shown in FIG. 8B. Thetechniques of concept-based snippet scoring, presented in this section,can be applied (with the appropriate changes) to any other suitable formof input query (e.g., an input query comprised of multiple pages).

query_score iterates over each query term, “QT_curr,” of input_query(lines 3-4), and assigns each query term a value (called a“coefficient”) that depends upon the results of concept-based matchingbetween QT_curr and the snippet (called “snippet2score”) that receives aconcept-based score. A process for assigning a coefficient value to aquery term is shown in the pseudocode as six “Rules.” FIG. 7A, line 9 toFIG. 7B, line 12. Each time query_score is invoked on a pair of dataitems (i.e., upon a snippet and a query), any coefficient values,assigned from prior invocations of query_score, are ignored.

The rules of query_score are explained below in conjunction with theexample input_query 801 of FIG. 8B and the example “snippet2score” 1100of FIG. 11.

Example snippet 1100 is presented in diagrammatic form. It is shown asbeing composed of five sentences, 1110 to 1114, with each sentencerepresented as a rectangular region. Within each sentence, only thosewords, that match a keyword of query 801, are shown. Those words, thatare in a region of snippet 1100 that has been classified as indicating“Good” are enclosed in a dashed outline (i.e., the word “last” insentence 1112). Those words, that are in a region of snippet 1100 thathas been classified as indicating “Bad” are enclosed in a solid outline(i.e., the words “out of power” in sentence 1111 and the words“hand-held” in sentence 1114). Those words, that are in a region ofsnippet 1100 that has been classified as not indicating any pinnacleconcept are not enclosed in an outline (i.e., the word “battery” insentence 1110).

query_score, when iterating over the query terms of query “input_query,”can skip each query term where the “requirement status” is “excluded”since such terms can have no match between a concept property of thequery term and a concept indicated in a snippet.

In presenting the example query of FIG. 8B, it will be assumed that thequery terms are iterated over in numerical order, from 820 to 823. Queryterms 820 to 823 will also be referred to as QT820 to QT823.

For query term 820, its keyword “battery” matches the word “battery” ofsentence 1110. Further, query term 820 specifies, for its conceptproperty, that a matching sub-unit of a snippet need not indicate anypinnacle concept (specified by “concept property” being “none” for queryterm 820). Query term 820, and “battery” of sentence 1110, satisfy Rule2 (FIG. 7A, lines 15-18). Therefore, query term 820 is assigned acoefficient value of 1.0. In terms of the pseudocode, we can say thatQT820(coefficient)=1.0 (see pseudocode line 18). In general, Rule 2applies when the query term specifies no particular concept and akeyword of the query term has at least one match in the snippet.

For query term 821, its keyword phrase “out of power” matches the words“out of power” of sentence 1111. Further, query term 821 specifies, forits concept property, that a matching sub-unit of a snippet is preferredif it indicates the pinnacle concept “Bad.” The solid box around “out ofpower” indicates that this sub-unit of sentence 1111 has been classifiedas indicating “Bad.” Query term 821 and “out of power” of sentence 1111satisfy Rule 1 (FIG. 7A, lines 9-13). Therefore, in terms of thepseudocode, QT821(coefficient)=1.0 (see pseudocode line 13). In general,Rule 1 applies when the query term specifies a pinnacle concept and akeyword of the query term has at least one match in the snippet at alocation that references the same pinnacle concept.

In a first alternative scenario, if the words “out of power” of sentence1111 did not indicate any concept, then query term 821 and “out ofpower” of sentence 1111 would satisfy Rule 3 (FIG. 7A, lines 20-24). Inthis case, because the query term has a preference for the concept“Bad,” but the matched snippet text is concept-neutral,QT821(coefficient) drops from 1.0 to 0.1 (see pseudocode line 24). Ingeneral, Rule 3 applies when the query term specifies a pinnacle conceptand a keyword of the query term has at least one match in the snippet ata location that indicates no pinnacle concept.

In a second alternative scenario, if the words “out of power” ofsentence 1111 indicate “Good,” then query term 821 and “out of power” ofsentence 1111 would satisfy Rule 5 (FIG. 7B, lines 1-7). In this case,because the query term has a preference for the concept “Bad,” but thematched snippet text is concept-opposite, QT821(coefficient) drops from0.1 (of the first alternative scenario) to 0.001 (see pseudocode line7). In general, Rule 5 applies when the query term specifies a pinnacleconcept and a keyword of the query term has at least one match in thesnippet at a location that indicates the opposite (or correlative)pinnacle concept.

Query term 822, and its match to the word “last” of sentence 1112,operates in essentially the same way described above for query term 821and its match to the words “out of power” of sentence 1111: the queryterm specifies a concept property and the matching sub-unit of thesnippet indicates the same pinnacle concept causing Rule 1 to apply. Thedifference is that the shared pinnacle concept, for the query term andthe matching snippet text, is “Good” rather than “Bad.”

Query term 823, and its match to the word “hand-held” of sentence 1114,operates in a way similar to that described above for query term 820 andits match to the word “battery” of sentence 1110. The fact that“hand-held” indicates “Bad” is irrelevant to the application of Rule 2and QT823(coefficient)=1.0. However, because QT823 has a requirementstatus of Optional, Rule 6 (FIG. 7B, lines 9-12) also is executed, whichguarantees that absent Optional query terms do not receive a score ofzero. In this case, QT823 happens to be present, and the execution ofRule 6 leaves the score unchanged: 0.001+1*0.999=1.0.

In a third alternative scenario, however, if none of the keywords ofquery term 823 matched in snippet 1100, then Rule 4 and Rule 6 bothapply and QT823(coefficient) drops from 1.0 to 0.001: 0.001+1*0.0=0.001.In general, Rule 4 applies when no keyword term of the query termmatches anywhere in the snippet.

Once each query term has been assigned a coefficient value, a singlevalue (called a query score or “QS”), to express the level ofconcept-property to snippet matching, can be determined. An exampleprocedure for determining the QS value is depicted in FIG. 7B, lines16-22. As can be seen, the pseudocode computes the product of thecoefficient values.

For query page 801 and snippet 1100 discussed above, not considering anyof the alternative scenarios discussed, the QS is (1*1*1*1)=1. Note thatif just the third alternative scenario is considered, where optionalquery term 823 does not occur in snippet 1100, the QS score for snippet1100 is (1*1*1*0.001)=0.001. Thus the lack of matching an optional queryterm will not necessarily prevent a snippet from being included in thesearch results, but it will lower its ranking considerably.

The particular coefficient values presented in FIGS. 7A-7B, for Rules1-6, are simply exemplary and other values can be assigned, dependingupon the application.

For the example of FIGS. 7A-7B, each coefficient value is chosen todiffer from all other coefficient values by at least an order ofmagnitude. Snippet scores can therefore differ by orders of magnitudeeven if the snippets differ only slightly in content. However, whenresults are sorted (or ranked) according to score, items withdrastically different scores can still appear (in an output listing to auser) close together if there are few other items with intermediatescores.

Rules 1-5, of FIGS. 7A-7B, are an example of assigning coefficientvalues, to query-term-to-snippet matches, that are larger if the matchquality is greater. If more than one of Rules 1-5 is found to apply to aparticular pair of query term and snippet, the Rule that assigns thelargest coefficient value to the query term can be chosen.

In addition to the Rules shown in FIGS. 7A-7B, additional factors can betaken into account in order to further adjust the particular coefficientvalues assigned. For example, the coefficient assigned to a query termcan be adjusted downward if the keywords of the query term, that matchin the current snippet for which a QS score is being determined, arerelatively commonly occurring words.

5. FURTHER DETAILS

5.1. Pinnacle Concepts

5.1.1. Other Pinnacle Concepts

Two pinnacle concepts, whose identification has been focused-on herein,are “Good” and “Bad.” However, the techniques presented herein can beapplied to other pinnacle concepts. Other example pinnacle concepts are“Need” and “Purchase.”

The concept “Need” occurs when a unit of natural language discourserefers to a situation whose characterization, as either good or bad,depends upon a condition. If the condition is satisfied, a goodsituation is realized, while if the condition is not satisfied, a badsituation occurs. As with “Good” and “Bad,” “Need” can also be used asthe organizing concept for a CBDB. A CBDB(“Need”) can be created, forexample, by searching the Internet for all web pages that refer to theconcept “Need.” Snippets, surrounding such references, can be extractedfrom the web content and accumulated in CBDB(“Need”). If a user conductsa search of CBDB(“Need”), with keywords to focus on the particularneeder or thing needed, highly relevant snippets can be identified.

The pinnacle concept “Purchase” can also be used as the organizingconcept for a CBDB. The concept “Purchase” occurs when a unit of naturallanguage discourse refers to the concept of making a purchase.“Purchase” can be used as the organizing concept for a CBDB. ACBDB(“Purchase”) can be created, for example, by searching the Internetfor all web pages that refer to the concept “Purchase.” Snippets,surrounding such references, can be extracted from the web content andaccumulated in CBDB(“Purchase”). If a user conducts a search ofCBDB(“Purchase”), with keywords to focus on the particular item to bebought or sold, highly relevant snippets can be identified.

5.1.2. Multiple Pinnacle Concept Concept-Based Search

For some search topics, the combination of searching according to asingle pinnacle concept, along with further focusing by keywords, can beinsufficient. It can be useful, for example, to be able to searchaccording to a combination of two or more pinnacle concepts (referred toherein as a “multi-concept concept-based search” or MC concept-basedsearch).

For example, when searching the “Good” and “Bad” databases, ontechnology-related issues, the following pinnacle concepts can be usefuladjuncts (the following pinnacle concepts are presented as correlativepairs):

-   -   Much/Little    -   Large/Small    -   Fast/Slow    -   High/Low

Each of the above-listed pinnacle concepts is frequently used inconnection with describing the attributes of a technology.

Additional pinnacle concepts can be made searchable, in a CBDB, asfollows. When a snippet “snpt” is added to a CBDB, in addition toindexing “snpt” according to its keywords, it can also be indexedaccording to the pinnacle concepts referenced. During keyword-basedsearching of the CBDB, in addition to having the capability to expressquery terms that search by keyword, there is the capability to expressquery terms that search by indexed pinnacle concepts.

Pinnacle concepts can also be made searchable, in a CBDB, as follows.Once a list of snippets “snpt_list” has been produced, by the search ofa CBDB by keyword, “snpt_list” can be searched for those snippets thatrefer to an additional pinnacle concept or concepts. This can beaccomplished by applying a classification procedure, like“sentence_classify,” to one or more sentences of each snippet of“snpt_list.” sentence_classify can be augmented to identify, in additionto organizing concepts, references to the additional pinnacle concepts.Those snippets, that refer to the additional pinnacle concept orconcepts, can be returned as a search result to the user.

5.1.3. Deriving a Concept-Feature Database

Given any pinnacle concept “pinnacle_x,” this section describes fourmethods for deriving a concept feature set.

The first method can be referred to as “machine learning.” In thisapproach, a person is provided a large number of UNLDs (e.g.,sentences). With respect to “pinnacle_x,” the person marks each UNLD “u”as either a “hit” (i.e., “pinnacle_x” is used or expressed in “u”) or a“miss” (i.e., “pinnacle_x” is not used or expressed in “u”). Statisticalanalysis is performed, on the marked UNLDs, to determine which featurescorrelate with whether a UNLD is a “hit” or “miss.” A problem with themachine learning approach, however, is that performance of a reliablestatistical analysis, even on features that are relatively frequent,requires the person to mark an extremely large corpus of UNLDs. Forexample, the 5000th most common word in English only occurs, roughly, 20times for each one million words of text. Thus, even if a person marks acorpus of sentences that is comprised of one million words, the 5000thmost common word will only have occurred 20 times. This kind of lowfrequency of occurrence can lead to spurious correlations and,therefore, to unreliable or incorrect linguistic features. Machinelearning can also produce spurious correlations because the machinelearning procedures are able to apply no contextual knowledge to thecorpus that is being analyzed.

In the second method, a person reads various UNLDs and identifiesspecific linguistic features (e.g., lexical units) that, in thesubjective opinion of that person, indicate a reference to the pinnacleconcept for which a concept feature set is sought. To each linguisticfeature identified, the person can also assigns a numeric “level ofassurance” value that quantifies how likely it is, in the subjectiveopinion of that person, that the pinnacle concept at issue is actuallybeing expressed or used. An advantage of the second method, over thefirst method, is that a very large input corpus does not need to beanalyzed before low frequency linguistic features are identified. Adisadvantage of the second method, with respect to the first method, isthat it relies on subjective judgment rather than on objective analysisof empirical data.

In the third method, a person attempts to recall a list of linguisticfeatures that, in the subjective opinion of that person, indicate thepinnacle concept at issue, without such recall being elicited or aidedthrough examination of an input corpus. An advantage of this method isthat an initial list of linguistic features can be assembled veryquickly, since no input corpus need be analyzed. A disadvantage of thisapproach is its reliance on unelicited recall which is known, ingeneral, to be far less complete than elicited recall. Anotherdisadvantage of this approach is its reliance on subjective judgment.

In the fourth method a person starts with an initial list of linguisticfeatures and then utilizes one or more known language-reference tools tofind similar additional linguistic features. The person can selectappropriate items, from the list of similar additional linguisticfeatures and assign, to such selected linguistic features, a numeric“level of assurance” value. Example known language-reference toolsinclude the following: a dictionary, a thesaurus and an ontology. Abrief description, of how each of these language-reference tools can beused, is as follows.

The definitions of a dictionary can be searched for those that containlinguistic features of the initial list. Each word of the dictionary,whose definition contains a linguistic feature of the initial list, is alikely candidate for addition to concept feature set of the pinnacleconcept at issue.

A thesaurus can provide, for each linguistic feature of the initiallist, a list of synonyms. A disadvantage of a thesaurus, however, isthat a linguistic feature can be included in a concept feature set formany other reasons than synonymy. For example, a linguistic feature thatexpresses a pinnacle concept weakly should be in the same conceptfeature set with a linguistic feature that expresses the same pinnacleconcept strongly. For example, if the pinnacle concept is “Good,” both“nice” and “fantastic” should be included. However, words that varygreatly, in the strength with which they express a particular pinnacleconcept, are not synonyms.

The term “ontology,” as used herein, refers to a body of knowledge thatis intended to be a complete description of some well-defined subset ofthe world. An example type of ontology is encyclopedias. “WordNet” is anonline ontology provided by the Cognitive Science Laboratory, PrincetonUniversity, Princeton, N.J., U.S.A. Given a lexical unit of the Englishlanguage, WordNet can currently provide a list that includes: synonyms,antonyms, hypernyms, hyponyms, meronyms and holonyms. Other than itsricher potential output, in terms of the additional word classes it willconsider, WordNet can be used in a similar manner to that of athesaurus.

5.2. Snippet Formation

As discussed above (see, for example, section 3.1 on “Indexing”), asnippet can be formed during the process of “scanning” a document,sentence-by-sentence, and applying a classification process to eachsentence scanned to determine the pinnacle concepts referred to. If apinnacle concept is identified in a sentence “s,” for which snippetformation is appropriate (e.g., the pinnacle concept is the organizingconcept for a CBDB), a snippet can be formed around “s” to providesufficient context such that the snippet is understandable apart fromits source document. A specific issue to consider, in determiningsufficient context for “s,” is pronoun resolution. In the context ofsnippet size determination, the pronoun resolution problem can be statedas follows: if a pronoun occurs in “s,” it is desirable that the nounfor it appear in the snippet context that surrounds “s.” The larger thesnippet size, the more likely it is that all pronouns of “s” will beresolved. Counterbalancing pronoun resolution, however, is the need fora snippet to be small enough to permit fast comprehension by thesearcher.

In the search areas described above in 1.3.1 (“New Uses For An ExistingTechnology”) and 1.3.2 (“Finding A Technology To Address A Problem”), asnippet size of five sentences has been experimentally determined to bedesirable. An example five sentence snippet 1100 is shown in FIG. 11.Snippet 1100 can be formed because an organizing concept is found to bereferred to by sentence 1112 in a document “D.” Once sentence 1112 isidentified by a classification procedure, two sentence before (i.e.,sentences 1110 and 1111) and two sentences after (i.e., sentences 1113and 1114) can be added to snippet 1100 to provide sufficient context forsentence 1112. If, however, sentence 1112 is at the beginning of “D,”the sub-unit of the snippet corresponding to sentences 1110 and 1111cannot be formed. Similarly, if sentence 1112 is at the end of “D,” thesub-unit of the snippet corresponding to sentences 1113 and 1114 cannotbe formed.

5.3. Production Environment

FIG. 3 depicts an example computer system design in which the techniquesdescribed herein can be applied.

Cloud 330 represents data available via the Internet. Computer 310 canexecute a web crawling program, such as Heritrix, that finds appropriateweb pages and collects them in an input database 300. An alternative, oradditional, route for collecting input database 300 is to useuser-supplied data 300. For example, as discussed above in section 1.3.1(“New Uses For An Existing Technology”), such user-supplied data 300 caninclude the following: CD-ROMs, record-oriented databases (relational orotherwise) and a company intranet. A computer 311 can be used to process(e.g., reformat) such user-supplied data 300 for input database 300.

Computer 312 can perform what is referred to in section 1.2.2(“Two-Phase Approach”) as the indexing phase. The indexing phase scansthe input database for sentences that refer to an organizing concept(through a classification procedure like “sentence_classify”), producesa snippet around each such sentence and adds the snippet to theappropriate concept-based database. FIG. 3 depicts an exampleconcept-based database (CBDB) 301. In a system designed fortechnology-related searching, at least two such CBDBs could be produced:one with “Good” as the organizing concept and the other with “Bad” asthe organizing concept.

Databases 320 and 321 represent, respectively, stable “snapshots” ofdatabases 300 and 301. Databases 320 and 321 can provide stabledatabases that are available to service search queries entered by a userat a user computer 333. Such user query can travel over the Internet(indicated by cloud 332) to a web interfacing computer 314 that can alsorun a firewall program. Computer 313 can receive the user query andperform what is referred to in section 1.2.2 (“Two-Phase Approach”) asthe search phase. The search phase can use a keyword-based search engineto search CBDB 321. The results of the search phase can be stored in adatabase 302 that is private to the individual user. When a snippet ofinterest is found in the search results, input database 320 is availableto the user to provide the full document from which the snippet wasobtained.

5.4. Example Negation Propagation

FIGS. 12A-12E depicts five similar sentences, labeled 1200-1204, thatare intended to be illustrative of how occurrences of the negationQuantifier “Negation,” in a sentence, can interact at governing nodes.This section applies the following sub-sections of section 2(“Concept-Based Classification”): 2.2.2 (“Populate Parse Structure”),2.2.3 (“Quantifier Propagation”), 2.2.4.2.1 (“Thresholding”), 2.2.4.2.2(“Sum Values On Per-Concept Basis”) and 2.2.4.2.3 (“Apply PLQ”).

Sentence 1200 can be called the “base” sentence, of the group of fivesentences, and sentences 1201-1204 are the result of adding the word“no” or “never,” at different locations, to sentence 1200. Sentence 1200is comprised of the following two independent clauses: “storms cancelgames” and “organizers plan accordingly.” These independent clauses arereferred to as, respectively, the “storm clause” and the “organizersclause.” The two independent clauses are connected by the word “but,”which is an example coordinating conjunction.

A node-oriented parse structure of sentence 1200 is not shown (as wasshown for sentence 1000 in FIGS. 10C to 10L). However, one canappreciate that the link between a node for “but” and a node of thestorm clause is not of a type over which the “Negation” Quantifier (orany other Quantifier) can propagate (see section 2.2.3 “QuantifierPropagation”). Similarly, the link between a node for “but” and a nodeof the organizers clause is not of a type over which the “Negation”Quantifier (or any other Quantifier) can propagate. For the stormclause, the node for “cancel” is the governing node (because it is theverb of the clause) and, for the organizers clause, the node for “plan”is the governing node (because it is the verb of the clause).

Propagation, of just the “Negation” Quantifier, can proceed as followsfor sentence 1200. For the storm clause, only the lexical unit “cancel”refers to the “Negation” Quantifier. A concept-value pair “p1,” for theconcept “Negation,” can be initially populated at the node for “cancel”(such population can be performed in accordance with section 2.2.2“Populate Parse Structure”). Since “p1” is already at the governingnode, it propagates no further (when such propagation is performed inaccordance with section 2.2.3 “Quantifier Propagation”). Assuming thevalue portion of “p1” is thresholded to 1.0 (in accordance with section2.2.4.2.1 “Thresholding”) the total value for “Negation” remains at 1.0after summing (in accordance with section 2.2.4.2.2 “Sum Values OnPer-Concept Basis”) all “Negation” values at the node for “cancel.”After applying 1.0 as the exponent for −1.0 (in accordance with section2.2.4.2.3 “Apply PLQ”) a value of −1.0 is determined for “Negation”concept. The value of −1.0 means that the storm clause, within thecontext of sentence 1200, asserts a single negative. This interpretationof sentence 1200 is, in fact, correct since the sentence does assertthat games do not take place. A similar analysis does not need to beperformed for the organizers clause of sentence 1200 since it has nolexical unit that refers to the “Negation” Quantifier. Therefore, theorganizers clause asserts that planning does take place.

Propagation, of just the “Negation” Quantifier, can proceed as followsfor sentence 1201. As with sentence 1200, a concept-value pair “p1,” forthe concept “Negation,” can be initially populated at the node for“cancel.” Unlike sentence 1200, however, the lexical unit “no” alsorefers to the “Negation” Quantifier. A concept-value pair “p2,” also forthe concept “Negation,” is also initially populated at a node for “no.”The concept-value pair “p2” can propagate to the node for “games” (wherewe shall refer to it as “p3”) since “no” modifies “games.” Theconcept-value pair “p3” can then propagate to the node for “cancel”(where we shall refer to it as “p4”) since “games” is the patient of theverb “cancel.” Thus, as a result of propagation, there will be twoconcept-value pairs, for the concept “Negation,” at the node for“cancel”: “p1” and “p4.” Assuming the values of both “p1” and “p4”threshold to 1.0, the presence of “p1” and “p4” at a single nodeindicate that the storm clause of sentence 1201 asserts a doublenegative. In terms of sections 2.2.4.2.2 (“Sum Values On Per-ConceptBasis”) and 2.2.4.2.3 (“Apply PLQ”), this double negative is determinedas follows. Summing the values of “p1” and “p4” produces a “Negation”value of 2.0 that is applied as an exponent 2.0 to the value −1.0. Thus,the double negative is represented as (−1.0)^(2.0), or simply 1.0. Thisis, in fact, a correct interpretation since the storm clause, within thecontext of sentence 1201, asserts that games do take place. A similaranalysis does not need to be performed for the organizers clause ofsentence 1201 since it has no lexical unit that refers to the “Negation”Quantifier. Therefore, the organizers clause asserts that planning doestake place.

Propagation, of just the “Negation” Quantifier, can proceed as followsfor sentence 1202. A concept-value pair “p1,” for the concept“Negation,” can be initially populated at the node for “cancel.” Aconcept-value pair “p2,” also for the concept “Negation,” is alsoinitially populated at a node for “no.” The concept-value pair “p2” canpropagate to the node for “storms” (where we shall refer to it as “p3”)since “no” modifies “storms.” The concept-value pair “p3” can thenpropagate to the node for “cancel” (where we shall refer to it as “p4”)since “storms” is the agent of the verb “cancel.” Thus the end result ofthe propagation is the same as for sentence 1201: there will be the twoconcept-value pairs “p1” and “p4,” for the concept “Negation,” at thenode for “cancel.” Assuming the values of both “p1” and “p4” thresholdto 1.0, the presence of “p1” and “p4” at a single node indicate that thestorm clause of sentence 1202 asserts a double negative (i.e., theclause asserts that games do take place). A similar analysis does notneed to be performed for the organizers clause of sentence 1202 since ithas no lexical unit that refers to the “Negation” Quantifier. Therefore,the organizers clause asserts that planning does take place.

Propagation, of just the “Negation” Quantifier, can proceed as followsfor sentence 1203. A concept-value pair “p1,” for the concept“Negation,” can be initially populated at the node for “cancel.” Aconcept-value pair “p2,” also for the concept “Negation,” is alsoinitially populated at a node for “never.” The concept-value pair “p2”can propagate to the node for “cancel” (where we shall refer to it as“p3”) since “never” modifies “cancel.” Thus the end result of thepropagation is the same as for sentences 1201 and 1202: there are twoconcept-value pairs, for the concept “Negation,” at the node for“cancel.” Assuming the values of both concept-value pairs threshold to1.0, a determination is made that the storm clause of sentence 1203asserts a double negative (i.e., the clause asserts that games do takeplace). A similar analysis does not need to be performed for theorganizers clause of sentence 1203 since it has no lexical unit thatrefers to the “Negation” Quantifier. Therefore, the organizers clauseasserts that planning does take place.

Propagation, of just the “Negation” Quantifier, can proceed as followsfor sentence 1204. The propagation of “Negation” in the storm clause isthe same as described above for sentence 1200. Therefore, the stormclause asserts that games do not take place. The propagation of“Negation,” for the organizers clause, is as follows. a concept-valuepair “p2,” for the concept “Negation,” is initially populated at a nodefor “never.” The concept-value pair “p2” can propagate to the node for“plan” (where we shall refer to it as “p3”) since “never” modifies“plan.” Assuming the value of “p3” thresholds to 1.0, it can beconcluded that the organizers clause, within the context of sentence1204, asserts a single negative. This interpretation of sentence 1204is, in fact, correct since the sentence does assert that planning doesnot take place.

6. GLOSSARY OF SELECTED TERMS

-   -   Classification: Identification of one or more pinnacle concepts        as asserted by a unit of natural language discourse or UNLD. A        typical UNLD is a sentence. For each such pinnacle concept        asserted, a value can be assigned indicating the reference level        of such reference. The particular sub-units of the UNLD,        responsible for each pinnacle concept asserted, can be        identified. An example sub-unit level, at which to identify such        responsibility, is the lexical unit level.    -   Concept-based database (CBDB): A database of snippets, where all        snippets of the database have been determined to refer to a        pinnacle concept that is called the “organizing concept” of the        database.    -   Concept-value pair: Refers not only to a pairwise data        representation, but also to any representation that is        functionally equivalent to a pairwise data representation. For        example, consider a sentence whose parse structure uses a matrix        data organization. In this case each row can correspond to a        structural unit of the sentence (e.g., a lexical unit) and each        column can correspond to a pinnacle concept. Each cell of the        matrix can function as a concept-value pair since it can be        assigned a value indicative of whether the concept represented        by the cell's column is referred-to by the structural unit        represented by the cell's row.    -   CFDB: Concept Feature Database. Contains a set of linguistic        features which, if found in a UNLD, indicate that the UNLD        refers to at least one pinnacle concept.    -   Computer-accessible content: any type of content that is        accessible via computer. This includes database content as well        as streaming sources of data.    -   Database: any corpus of data that is accessible by computer.    -   Keyword-based search: The process by which a UNLD of interest        can be identified within a larger database based on the presence        or absence of pre-selected query terms within that UNLD. In the        simplest implementation, the query is an exact word or phrase.        One elaboration allows for each query to be a pattern that        specifies a set of possible matching words or phrases. One        common manner of elaboration is to allow a word to be        substituted by any of its grammatical forms (e.g., “written,”        “writes,” and “wrote” all matching a query of “write”). Another        common manner of elaboration is to allow expressions of queries        linked together with the operators of standard or nonstandard        logics, where the expression is deemed to be present if each        internal term is interpreted as a subquery, and the expression,        applied to those subqueries evaluates to true.    -   Lexical unit: A sequence of one or more words that has at least        one meaning “m” for which the sequence operates as an        indivisible unit. Meaning “m” cannot be derived from the        sequence through any normal composition of the meanings of the        sequence's constituent words. For example, “The White House” is        not simply any house which happens to be white, and “dry ice” is        not simply ice that happens to be dry.    -   Parse structure: Any data representation that specifies a UNLD        as a division into parts and that maintains relationship        information between those parts. Example organizational schemes,        for the parts of a parse structure, can include any of the        following: matrix, linear ordering, tree structure, directed        acyclic graph or network.    -   Propagation: Refers to the transfer or copying of data, that has        been associated with certain parts of a data structure, to other        parts of that data structure.    -   Pseudo-code: The pseudo-code presented herein is loosely based        on the C programming language. The C programming language is        described in such texts as “A Book on C,” by A. Kelley and I.        Pohl, Benjamin Cummings Pub. Co., Third Edition, 1995, ISBN        0-8053-1677-9, herein incorporated by reference in its entirety.    -   Record: Any representation of data that is recognized, for the        database of interest, as a discretely accessible unit.    -   UNLD: Refers to a “unit of natural language discourse unit.” The        term “UNLD” can be used to refer to any unit of a natural        language discourse. For example, a UNLD can refer to a unit that        is of arbitrary length or that is not associated with any        general linguistic structure.

While the invention has been described in conjunction with specificembodiments, it is evident that many alternatives, modifications andvariations will be apparent in light of the foregoing description.Accordingly, the invention is intended to embrace all such alternatives,modifications and variations as fall within the spirit and scope of theappended claims and equivalents.

What is claimed is:
 1. A method for assigning a score for ranking arecord, given the record and a query, comprising: identifying, performedat least in part with a configuration of computing hardware andprogrammable memory, a first query term, of the query; identifying,performed at least in part with a configuration of computing hardwareand programmable memory, a first pinnacle concept property of the firstquery term; identifying, performed at least in part with a configurationof computing hardware and programmable memory, a first set ofoccurrences of the first query term in the record; identifying,performed at least in part with a configuration of computing hardwareand programmable memory, a first set of sub-units of the record, whereineach sub-unit contains a member of the first set of occurrences;determining, performed at least in part with a configuration ofcomputing hardware and programmable memory, for a first sub-unit of thefirst set of sub-units, whether a first concept, referenced by the firstsub-unit, is a pinnacle concept, and identification of the first conceptas a pinnacle concept indicates that the first concept is not a plainsconcept; assigning, performed at least in part with a configuration ofcomputing hardware and programmable memory, a set of pinnacle conceptsto each member of the first set of sub-units, wherein a pinnacle conceptis a member, of a set of pinnacle concepts, if the pinnacle concept isasserted by the sub-unit, of the first set of sub-units, to which it isassigned; determining whether the first pinnacle concept propertyspecifies a first pinnacle concept; assigning, if the first pinnacleconcept is specified, a first score to the first query term that islarger when the first pinnacle concept is a member of a set of pinnacleconcepts of the first set of sub-units than when the first pinnacleconcept is not a member of a set of pinnacle concepts of the first setof sub-units; assigning, if the first pinnacle concept is not specified,a first score to the first query term that is larger when the first setof sub-units is not empty than when the first set of sub-units is empty;assigning, performed at least in part with a configuration of computinghardware and programmable memory, a first score to the first query termas a function of the first pinnacle concept property and first set ofsub-units; and assigning, performed at least in part with aconfiguration of computing hardware and programmable memory, a score,for ranking the record, as a function of the first score.
 2. The methodof claim 1, further comprising: determining that the first pinnacleconcept property specifies a first pinnacle concept; determining thatthe first pinnacle concept is not a member of a set of pinnacle conceptsof the first set of sub-units; and assigning a first score to the firstquery term that is larger when at least one set of pinnacle concepts,for a sub-unit of the first set of sub-units, is empty of a correlativepinnacle concept of the first pinnacle concept than when at least oneset of pinnacle concepts, for a sub-unit of the first set of sub-units,contains a correlative pinnacle concept of the first pinnacle concept.3. The method of claim 1, further comprising: identifying a second queryterm, of the query; identifying a second pinnacle concept property ofthe second query term; identifying a second set of occurrences of thefirst query term in the record; identifying a second set of sub-units ofthe record, wherein each sub-unit contains a member of the second set ofoccurrences; assigning a set of pinnacle concepts to each member of thesecond set of sub-units, wherein a pinnacle concept is a member, of aset of pinnacle concepts, if the pinnacle concept is asserted by thesub-unit, of the second set of sub-units, to which it is assigned;assigning a second score to the second query term as a function of thesecond pinnacle concept property and second set of sub-units; andassigning a score, for ranking the record, as a function of the firstand second scores.
 4. The method of claim 3, wherein the function of thefirst and second scores determines a product of the first and secondscores.
 5. The method of claim 1, further comprising: applying aclassification procedure to the record to determine a set of pinnacleconcepts referenced by sub-units of the record.
 6. The method of claim1, further comprising: searching a first database, according to thequery, to produce a first search result of which the record is a part;assigning a score, for ranking a record, to records of the first searchresult other than the record; and ranking records of the first searchresult according to the score for ranking a record.
 7. The method ofclaim 1, wherein the record represents a snippet.
 8. The method of claim1, wherein a sub-unit is a sentence.
 9. A system, for assigning a scorefor ranking a record, given the record and a query, comprising: asub-system configured, as a result of its computing hardware andprogrammable memory, to accomplish identifying a first query term, ofthe query; a sub-system configured, as a result of its computinghardware and programmable memory, to accomplish identifying a firstpinnacle concept property of the first query term; a sub-systemconfigured, as a result of its computing hardware and programmablememory, to accomplish identifying a first set of occurrences of thefirst query term in the record; a sub-system configured, as a result ofits computing hardware and programmable memory, to accomplishidentifying a first set of sub-units of the record, wherein eachsub-unit contains a member of the first set of occurrences; a sub-systemconfigured, as a result of its computing hardware and programmablememory, to accomplish determining, for a first sub-unit of the first setof sub-units, whether a first concept, referenced by the first sub-unit,is a pinnacle concept, and identification of the first concept as apinnacle concept indicates that the first concept is not a plainsconcept; a sub-system configured, as a result of its computing hardwareand programmable memory, to accomplish assigning a set of pinnacleconcepts to each member of the first set of sub-units, wherein apinnacle concept is a member, of a set of pinnacle concepts, if thepinnacle concept is asserted by the sub-unit, of the first set ofsub-units, to which it is assigned; a sub system configured toaccomplish determining, of whether the first pinnacle concept propertyspecifies a first pinnacle concept: a sub system configured toaccomplish assigning, if the first pinnacle concept is specified, of afirst score to the first query term that is larger when the firstpinnacle concept is a member of a set of pinnacle concepts of the firstset of sub-units than when the first pinnacle concept is not a member ofa set of pinnacle concepts of the first set of sub-units; a sub systemconfigured to accomplish assigning, if the first pinnacle concept is notspecified, of a first score to the first query term that is larger whenthe first set of sub-units is not empty than when the first set ofsub-units is empty; a sub-system configured, as a result of itscomputing hardware and programmable memory, to accomplish assigning afirst score to the first query term as a function of the first pinnacleconcept property and first set of sub-units; and a sub-systemconfigured, as a result of its computing hardware and programmablememory, to accomplish assigning a score, for ranking the record, as afunction of the first score.
 10. The system of claim 9, furthercomprising: a sub system configured to accomplish determining, that thefirst pinnacle concept property specifies a first pinnacle concept; asub system configured to accomplish determining, that the first pinnacleconcept is not a member of a set of pinnacle concepts of the first setof sub-units; and a sub system configured to accomplish assigning, of afirst score to the first query term that is larger when at least one setof pinnacle concepts, for a sub-unit of the first set of sub-units, isempty of a correlative pinnacle concept of the first pinnacle conceptthan when at least one set of pinnacle concepts, for a sub-unit of thefirst set of sub-units, contains a correlative pinnacle concept of thefirst pinnacle concept.
 11. The system of claim 9, further comprising: asub system configured to accomplish identifying, of a second query termof the query; a sub system configured to accomplish identifying, of asecond pinnacle concept property of the second query term; a sub systemconfigured to accomplish identifying, of a second set of occurrences ofthe first query term in the record; a sub system configured toaccomplish identifying, of a second set of sub-units of the record,wherein each sub-unit contains a member of the second set ofoccurrences; a sub system configured to accomplish assigning, of a setof pinnacle concepts to each member of the second set of sub-units,wherein a pinnacle concept is a member, of a set of pinnacle concepts,if the pinnacle concept is asserted by the sub-unit, of the second setof sub-units, to which it is assigned; a sub system configured toaccomplish assigning, of a second score to the second query term as afunction of the second pinnacle concept property and second set ofsub-units; and a sub system configured to accomplish assigning a score,for ranking the record, as a function of the first and second scores.12. The system of claim 11, wherein the function of the first and secondscores determines a product of the first and second scores.
 13. Thesystem of claim 9, further comprising: a sub system configured toaccomplish applying, of a classification procedure to the record todetermine a set of pinnacle concepts referenced by sub-units of therecord.
 14. The system of claim 9, further comprising: a sub systemconfigured to accomplish searching of a first database, according to thequery, to produce a first search result of which the record is a part; asub system configured to accomplish assigning a score, for ranking arecord, to records of the first search result other than the record; anda sub system configured to accomplish ranking, of records of the firstsearch result according to the score for ranking a record.
 15. Thesystem of claim 9, wherein the record represents a snippet.
 16. Thesystem of claim 9, wherein a sub-unit is a sentence.